Heart Rate and Heart Rate Variability in Healthy Preterm-Born Young Adults and Association with Vitamin D: A Wearable Device Assessment

Prematurity has been associated with impaired parasympathetic cardiac regulation later in life. Changes in heart rate (HR) and heart rate variability (HRV) may indicate a risk for future cardiac dysfunction. The putative role of Vitamin D on cardiac autonomic function in individuals born preterm (PT) remains unknown. This study involves monitoring autonomic cardiac regulation and Vitamin D concentrations in 30 PT and 16 full-term (FT) young adults in a free-living context. The PT subjects were born between 1994 and 1997 at Oulu University Hospital. The inclusion criteria were (1) being born ≤ 32 gestation weeks or (2) being born < 34 gestation weeks with a birth weight under 1500 g. Participants wore an Oura ring sleep tracer, a smart ring device, for 2 weeks to monitor cardiac autonomic function. Parameters related to autonomic cardiac regulation, lowest nighttime resting HR, and the root mean square of successive differences (RMSSD) to describe HRV were collected. PT males exhibited a tendency toward lower RMSSD (71.8 ± 22.6) compared to FT males (95.63 ± 29.0; p = 0.10). Female participants had a similar mean RMSSD in the FT and PT groups at 72.04 ± 33.2 and 74.0 ± 35.0, respectively. Serum 25-hydroxyvitamin D concentration did not correlate with cardiac autonomic function parameters. When assessing the lowest resting nighttime HRs and HRVs in a long-term, real-world context, healthy female PT young adults performed similarly to their FT peers. In contrast, the present study's results suggest that male PT young adults exhibit impaired autonomic cardiac function, potentially putting them at risk for cardiovascular disease later in adulthood.

Longitudinal study of vitamin D status among Thai individuals in a sun-abundant country

Background

Vitamin D deficiency is a major public health problem worldwide, even in countries with abundant sunshine. Understanding the risk factors for vitamin D deficiency is important to inform public health recommendations. We conducted a longitudinal analysis of vitamin D status in Thai individuals to assess changes in vitamin D status over time and identify potential determinants.

Study design

This study is a long term prospective cohort study.

Methods

Of the 1239 participants who were employees of the Electricity Generating Authority of Thailand, serum 25-hydroxyvitamin D (25(OH)D) levels were measured by liquid chromatography/tandem mass spectrometry from samples collected in 2009 and 2019.

Results

There was a significant 14.8% increase in serum total 25(OH)D (P < 0.001) from 2009 to 2019, which resulted from significant increases in both 25(OH)D3 and 25(OH)D2. The epimeric form of 25(OH)D2 also increased significantly, while there was no increase in the epimeric form of 25(OH)D3. A univariate analysis showed significant associations between increased total 25(OH)D and increasing age, male sex, and lower body mass index. After controlling for baseline vitamin D status, multivariate regression analyses found that the direction of association and significance from univariate analyses persisted for total 25(OH)D and 25(OH)D3. However, a univariate association found between female sex and an increase in 25(OH)D2 was not significant in multivariate regression analysis.

Conclusions

A long-term trend of improved vitamin D status was found among Thai adult individuals over a 10-year period; however, improvements were less noticeable in women.

Relationship between vitamin D, iron, and hepcidin in premenopausal females, potentially confounded by ethnicity

PURPOSE

To investigate the associations between vitamin D, hepcidin, and iron status in premenopausal females of different ethnic cohorts residing in Auckland, New Zealand (NZ).

METHODS

A total of 160 females aged 18-45 years participated in a cross-sectional study. Demographics, body composition, serum 25(OH)D, inflammatory markers (C-reactive protein and interleukin-6, IL-6), and iron biomarkers (serum ferritin, haemoglobin, soluble transferrin receptor, and hepcidin) were measured. Comparisons between parametric, non-parametric, and categorical variables were completed by using one-way ANOVA, Kruskal-Wallis, and Chi-squared tests, respectively. ANCOVA was used to compare serum 25(OH)D across iron parameter categories.

RESULTS

Of the 160 participants, 60 were NZ European, 67 were South Asian, and 33 were from the 'other' ethnic groups. South Asians had significantly higher body fat percentage (BF%) and IL-6 concentration (38.34% and 1.66 pg·mL-1, respectively), compared to NZ Europeans (27.49% and 0.63 pg·mL-1, respectively, p < 0.001). South Asians had significantly lower 25(OH)D concentrations compared to NZ Europeans (33.59 nmol·L-1 vs 74.84 nmol·L-1, p < 0.001). In NZ Europeans, higher 25(OH)D concentration was seen in those with lower (≤ 3.5 nM) hepcidin concentration, p = 0.0046. In South Asians, higher 25(OH)D concentration was seen in those with higher (> 3.5 nM) hepcidin concentrations, p = 0.038. There were no associations between serum 25(OH)D and serum ferritin.

CONCLUSION

Within South Asian women, an unexpected positive relationship between 25(OH)D and hepcidin concentration was observed which may be due to significantly higher IL-6 concentrations, BF%, and lower 25(OH)D concentrations. Future research is required to confirm these observations in this ethnic cohort.

Update on vitamin D status in sunshine-abundant Thailand, 2019-2020

OBJECTIVE

The prevalence of vitamin D deficiency worldwide remains unknown. In the Thai 4th National Health Examination Survey (2008-2009) cohort, ∼45% and 7% of the adult population had serum 25-hydroxyvitamin-D [25(OH)D] levels below the threshold of 75 and 50 nmol/L, respectively. Vitamin D has been a hot topic in the scientific community. The aim of this study was to uncover the current situation regarding vitamin D status in Thailand.

METHODS

Participants were 4098 adults ages 10 to 96 y, randomly selected from the Thai 6th National Health Examination Survey (2019-2020) cohort. Serum 25(OH)D levels were measured by liquid chromatography/tandem mass spectrometry. Data were expressed as mean ± SE and adjusted odds ratio (95% CI).

RESULTS

Mean vitamin D status based on serum 25(OH)D was 88.2 nmol/L and differed by age, sex, residency, and religion. The prevalence of serum 25(OH)D <75 and <50 nmol/L were 31% and 4%, respectively. The prevalence of vitamin D deficiency was lower in individuals who lived in the northeastern part of Thailand or were male. The risk for vitamin D deficiency was lower than that in 2009. In multiple linear regression analysis, female sex, younger age, urbanization, a higher body mass index, Muslim religion, and living in Bangkok or the central region of Thailand were independently associated with lower serum 25(OH)D levels.

CONCLUSIONS

The vitamin D status in the Thai population has improved over the past 10 y. This improvement may reflect an increased awareness related to adequate vitamin D status.

Hand grip strength, vitamin D status, and diets as predictors of bone health in 6-12 years old school children

BACKGROUND

Vitamin D and calcium-rich foods, exposure to sunlight, and physical activities (PA) play a pivotal role in promoting the production of sufficient vitamin D and improving grip strength needed for better bone health among school children.

PURPOSE

This study aimed to determine the effects of hand grip muscle strength (HGS), vitamin D in addition to diets, and PA on bone health status among 6-12 years old schoolchildren.

METHODS

This study was based on a cross-sectional observational design, which was descriptive in nature. A diverse sample of 560 elementary school children aged 6-12 years old were invited to participate in this descriptive cross-sectional study. The Dual-Energy X-Ray Absorptiometry (DXA), QUS technique, and ACTi graph GT1M accelerometer were used respectively as a valid tools to identify BMD, BMC, and other parameters of bone health like c-BUA values and bone stiffness (SI), and physical activity (PA) of all individuals participated in this study. In addition, a hydraulic dynamometer was used to measure hand grip strength among the participants. Moreover, an immunoassay technique was used to measure the serum levels of vitamin 25(OH)D level, and bone metabolism markers; NTX, DPD, Ca, and sBAP in all participants. Bone loss (osteoporosis) was cross-sectionally predicted in 19.64% of the total population, most of whom were girls (14.3% vs. 5.4% for boys; P = 0.01). Compared to boys, the incidence of osteoporosis was higher and significantly correlated in girls with lower HGS, deficient vitamin D, inadequate vitamin D and Ca intake, greater adiposity, poor PA, and lower sun exposure. Also, in girls, lower vitamin 25(OH)D levels, and poor HGS were shown to be significantly associated with lower values of BMD, BMC, SI, and higher values of bone resorption markers; NTX, DPD, and sBAP and lower serum Ca than do in boys. The findings suggested that deficient vitamin D, lower HGS, adiposity, PA, and sun exposure as related risk factors to the pravelence of bone loss among school children, particularly in girls. In addition, these parameters might be considered diagnostic non-invasive predictors of bone health for clinical use in epidemiological contexts; however, more studies are required.

Sufficient vitamin D is favorable for children with persistent and chronic immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia in the absence of other disorders. Vitamin D (VD) has been shown to modulate the immune system and its deficiency is linked to many immunological disorders. Supplementation with VD in ITP has promising results. This work aims at evaluating VD values in children with persistent and chronic ITP and the effect of its deficiency on disease severity and treatment response. A case-control study including 50 persistent and chronic ITP patients and 50 healthy controls was conducted. 25 OH vitamin D level was determined using ELISA technique. VD median value was significantly higher among the control group than that of the patients' group (28 vs 21.5 and p = 0.002). Severe deficiency was detected significantly more among the patients' group than the control group (12 (24%) vs 3 (6%), p = 0.048) respectively. Forty-four percent of complete responders belong to sufficient VD category ((15/34) ~ 44% (p = 0.005)) representing all patients with sufficient VD status (n = 15). Also, a positive correlation between serum level of vitamin D and mean PLT count was observed (r = 0.316, p value = 0.025). Sufficient vitamin D was associated with better treatment response and less disease severity. Vitamin D supplementation may be a new therapeutic option for chronic ITP.

Influence of vitamin D metabolites on vitamin D status, immunity and gut health of piglets

Immediately post-weaning, piglets are prone to gastrointestinal infectious diseases. The active metabolite of vitamin D 1,25-dihydroxyvitamin D has direct impact on immune cell function and responses. Thus, a low vitamin D status may compromise the immune responses during infectious diseases. The aim of this study was to examine the effect of supplementation of different forms of vitamin D (25-OH-D₃ and vitamin D₃) to suckling piglets' vitamin D status at weaning. In addition, to determine whether the vitamin D status could affect the immune development in piglets and their robustness against E. coli challenge. Genetically E. coli F4 susceptible litters of piglets were divided into two treatment groups: group 1 (n = 16) provided milk formula supplemented with vitamin D₃ (CON), and group 2 (n = 16) provided milk formula supplemented with 25-OH-D₃ (TREAT). Piglets were offered the experimental milk formulas from day 3 after farrowing until weaning (at day 28 of age). A commercial weaner diet with high protein content were provided to induce weaning stress. Milk formulas, sow and weaner diets as well as plasma and milk samples obtained from sows (n = 8) were analysed for vitamin D metabolites. Vitamin D status in piglets was investigated by collection of plasma samples on day 3, 15, 28 and 35 of age. Eight piglets randomly selected from each dietary group (in total 16 pigs) were inoculated with E. coli F4 O149 on day 2 and 3 post-weaning. Blood samples collected on day 2 and 9 post-weaning (pre- and post E. coli inoculation, respectively) were analysed for haematological and immunological parameters including immunoglobulins, antibodies specific to E. coli O149 K88, cytokines and C-reactive protein. In addition, intestinal samples were obtained one week after E. coli inoculation to study the influence of infection and vitamin D status on immune responses at different sites of the intestine. This was accomplished by gene expression of various cytokines and tight junction proteins. In general, vitamin D status of the piglets were low. However, piglets provided TREAT during the suckling period had increased vitamin D status at weaning compared to piglets provided CON. Vitamin D was used during activation of the immune system as pigs inoculated with E. coli had lower plasma concentrations of 25-OH-D₃ than non-inoculated pigs possibly due to mobilising of vitamin D in the liver. Hence, increased vitamin D status at weaning might improve piglets' resistance to E. coli infection.

The relationship between hematological indices as indicators of inflammation and 25-hydroxyvitamin D3 status in newborns

BACKGROUND

There is still much unknown about the relationship between hematological parameters and vitamin D status in newborns. The aim of the study is to evaluate the relationship between 25(OH)D3 (vitamin D) status and new defined systemic inflammatory markers neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), and platelet to lymphocyte ratio (PLR) in newborns.

METHODS

One hundred newborns were enrolled in the study. Serum vitamin D status, below < 12 ng/mL (< 30 nmol/L) as deficient, 12-20 ng/mL (30-50 nmol/L) as insufficient, and > 20 ng/mL (> 50 nmol/L) was considered as sufficient.

RESULTS

Parallel to maternal and newborn vitamin D status were also statistically different between the groups (p < 0.05). Moreover, there was a statistically significant difference was found between the deficient, sufficient and insufficient groups in terms of newborn hemoglobin, neutrophil, monocytes, NLR, PLT, PLR and neutrophil to monocyte ratio (NMR) (p < 0.05, in all). There was also a positive correlation between maternal and newborn vitamin D status (r = 0.975, p = 0.000). The newborn NLR were negative correlated with newborn vitamin D status (r = -0.616, p = 0.000).

CONCLUSIONS

The results of this study suggest that there may be potential new biomarkers to predict inflammation associated with the inflammatory state that may arise due to changes in NLR, LMR, and PLR in vitamin D deficiency in newborns. NLR and other hematologic indices may be non-invasive, simple, easily measurable, cost-effective markers of inflammation in newborns.

Vitamin D Status in Osteoporotic and Diabetic Patients and Athletic Healthy Individuals from Northern Greece

Background

Vitamin D deficiency is recognised as a pandemic in the developed world. However, the importance of prudent sun exposure tends to be overlooked, which is responsible for this pandemic.

Methods

We investigated the vitamin D status in 326 adults, 165 females and 161 males: 99 Osteoporosis patients, 53 Type 1 Diabetes patients, 51 Type 2 Diabetes patients, and 123 Athletic Healthy individuals, from Northern Greece, through the measurement of total calcidiol in winter and summer by immunoenzymatic assay.

Results

In the Whole Sample 23.31% had severe deficiency, 13.50% mild deficiency, 17.48% insufficiency, and 45.71% adequacy at the end of winter. Mean concentrations differed significantly (p <0.001) between males and females. The prevalence of deficiency in the young was significantly lower than in the middle-aged (p = 0.004) and in the elderly (p <0.001), while it was significantly lower (p = 0.014) in the middle-aged than in the elderly. The best vitamin D status was found in the Athletic Healthy individuals, followed by the Type 1 and Type 2 Diabetic patients, while Osteoporotic patients had the poorest status. The difference in mean concentrations between winter and summer was significant (p <0.001).

Conclusions

Vitamin D status deteriorated with increasing age and it was better in males than in females. Our findings suggest that outdoor physical activity in a Mediterranean country can cover the vitamin D needs of the young and the middle-aged, but not of the elderly, without the need for dietary supplements.

Effects of vitamin D on associations between air pollution and mental health outcomes in Korean adults: Results from the Korea National Health and Nutrition Examination Survey (KNHANES)

BACKGROUND

Evidence suggests that low individual vitamin D levels enhance adverse effects associated with air pollution on mental health conditions. The aim of this study was to identify associations between ambient air pollution exposure, mental health, and serum vitamin D status in the general population of South Korea.

METHODS

We included national representative data for 29,373 adults in the final analysis. We measured serum 25-hydroxyvitamin D concentrations to assess vitamin D status for each participant. We assessed mental health factors (i.e., perceived stress, depressive symptoms, and suicidal ideation), and analyzed associations between these factors and individuals' annual average exposures to air pollutants, including particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide, and carbon monoxide (CO).

RESULTS

Using an adjusted model, we found PM₁₀ affected mental health outcomes, such as perceived stress (odds ratio [OR] = 1.04; 95 % confidence interval [CI] = 1.00-1.09), depression symptoms (OR = 1.12; 95 % CI = 1.06-1.18), and suicidal ideation (OR = 1.11; 95 % CI = 1.05-1.17). Effects of the pollutants NO₂ and CO were significant only in the group with perceived stress and depressive symptoms. PM₁₀ and NO₂ exposures were significantly associated with increased odds of adverse mental health in participants with vitamin D deficiency.

LIMITATIONS

Since the cross-sectional design of KNHANES data, it is not possible to evaluate the causal relationship between air pollution exposure, vitamin D status and mental health.

CONCLUSIONS

This study results suggest that associations between ambient air pollution and mental health outcomes were stronger in participants with vitamin D deficiency.

Prevalence and risk factors for vitamin D insufficiency in 6-12-month-old infants: a cross-sectional study in Southern Thailand

BACKGROUND

Vitamin D is an essential micronutrient for bone mineralization and bone growth in children. There have been few studies to date of vitamin D status in infants aged 6-12 months in Southeast Asian countries.

AIM

To examine the prevalence of vitamin D insufficiency (VDI, including vitamin D deficiency) in healthy infants and the risk factors for VDI in southern Thailand.

METHODS

A cross-sectional study was carried out in 120 healthy infants aged 6-12 months and their mothers. Blood samples were obtained for measurement of serum calcium, phosphate, alkaline phosphatase, albumin, parathyroid hormone and 25-hydroxyvitamin D (25OHD) levels. The mothers were interviewed for their infants feeding intake, sunlight exposure, type of dress, and sunscreen use. Chi-square and t-test were used to compare between groups for categorical and continuous variables, respectively. Pearson correlation was used to identify the relationship between serum levels of 25OHD of the infants and other biochemical variables of the infants and serum levels of maternal 25OHD. Logistic regression analysis was used to identify the factors associated with vitamin D status.

RESULTS

The prevalence of VDI in our study infants was high at 28.3%, all of whom were mainly breastfed infants. Subgroup analysis of the mainly breastfed infants found that the risk factors for VDI were maternal VDI and a short duration of sunlight exposure. The serum 25OHD levels of the mainly breastfed infants were significantly positively correlated with the maternal serum 25OHD levels (r = 0.49, p-value < 0.01) and with sunlight exposure duration (r = 0.40, p-value < 0.01).

CONCLUSIONS

The prevalence of VDI was high in 6-12-month-old infants, particularly those who were mainly breastfed from VDI mothers, and who had short durations of sunlight exposure. As breast milk contains adequate amounts of most important vitamins and growth factors, breastfeeding is still encouraged for infants with 400 IU vitamin D daily supplementation to prevent VDI.

Vitamin D status and parathyroid hormone assessment in girls with central precocious puberty

PURPOSE

The objective of this study was to analyze vitamin D status and PTH concentrations in 6- to 8-year-old girls with central precocious puberty.

METHODS

A cross-sectional clinical and blood testing study (calcium, phosphorus, 25(OH)D and PTH) was carried out in 78 girls with central precocious puberty (CPP group), aged 6.1-7.9 years. A control group was recruited (137 prepubertal girls, aged 6.1-8.2 years). The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D.

RESULTS

There were no significant differences in vitamin D status between both groups. There were no significant differences in 25(OH)D concentrations between CPP (25.4 ± 8.6 ng/mL) and control groups (28.2 ± 7.4 ng/mL). In contrast, PHT concentrations in CPP group (44.8 ± 16.3 pg/mL) were higher (p < 0.05) with respect to control group (31.0 ± 11.9 ng/mL). In CPP group, there was a positive correlation (p < 0.05) between PTH concentrations and growth rate, bone age, and basal estradiol, basal FSH, basal LH and LH peak concentrations.

CONCLUSION

Vitamin D status in 6- to 8-year-old girls with CPP is similar to that in prepubertal girls. PTH concentrations were significantly higher in girls with CPP, and this could be considered as a physiological characteristic of puberty and, in this case, of pubertal precocity.

Adequacy of calcium and vitamin D nutritional status in a nationally representative sample of Irish teenagers aged 13-18 years

CONTEXT AND PURPOSE

In light of the key roles of vitamin D and calcium in adolescent bone health, there is a critical need for representative data on nutritional status for both micronutrients in teenagers. The present work used data from the recent representative National Teens' Food Survey II (2019-2020) to assess calcium and vitamin D intakes of teenagers in Ireland, including adequacy of such intakes, as well as, for the first time, to characterise serum 25-hydroxyvitamin D (25(OH)D) concentrations and their determinants.

METHODS

Usual calcium and vitamin D intake estimates were generated using food intake data (via 4-day weighed food records) from a nationally representative sample of teenagers aged 13-18 years in Ireland (n 428). Serum 25(OH)D was measured (via LC-MS/MS) in the 57.5% (n 246) who provided a blood sample.

RESULTS

Sixty-seven and 94% of Irish teenagers had intakes of calcium and vitamin D below the respective Estimated Average Requirements values, reflecting a high degree of inadequacy of intake for both micronutrients (and higher in girls than boys; P < 0.001). In addition, 21.7% and 33.1% of teenagers had serum 25(OH)D < 30 nmol/L (risk of vitamin D deficiency) and 30-49.9 nmol/L (inadequacy), respectively. Extended winter sampling, being aged 16-18 years, low total vitamin D intake, being overweight/obese or being of non-white skin type were significant (P < 0.05) predictors of serum 25(OH)D < 30 nmol/L.

CONCLUSIONS

There was a high prevalence of inadequacy of intake of calcium and vitamin D in Irish teenagers, and a fifth were at increased risk of vitamin D deficiency.

Maternal excess adiposity and serum 25-hydroxyvitamin D < 50 nmol/L are associated with elevated whole body fat mass in healthy breastfed neonates

BACKGROUND

Vitamin D status of pregnant women is associated with body composition of the offspring. The objective of this study was to assess whether the association between maternal vitamin D status and neonatal adiposity is modified by maternal adiposity preconception.

METHODS

Healthy mothers and their term appropriate weight for gestational age (AGA) infants (n = 142; 59% male, Greater Montreal, March 2016-2019) were studied at birth and 1 month postpartum (2-6 weeks). Newborn (24-36 h) serum was collected to measure total 25-hydroxyvitamin D [25(OH)D] (immunoassay); maternal pre-pregnancy BMI was obtained from the medical record. Anthropometry, body composition (dual-energy X-ray absorptiometry) and serum 25(OH)D were measured at 2-6 weeks postpartum in mothers and infants. Mothers were grouped into 4 categories based on their vitamin D status (sufficient 25(OH)D ≥ 50 nmol/L vs. at risk of being insufficient < 50 nmol/L) and pre-pregnancy BMI (< 25 vs. ≥25 kg/m2): insufficient-recommended weight (I-RW, n = 24); insufficient-overweight/obese (I-OW/O, n = 21); sufficient-recommended weight (S-RW, n = 69); and sufficient-overweight/obese (S-OW/O, n = 28). Partial correlation and linear fixed effects model were used while adjusting for covariates.

RESULTS

At birth, infant serum 25(OH)D mean concentrations were below 50 nmol/L, the cut-point for sufficiency, for both maternal pre-pregnancy BMI categories; 47.8 [95%CI: 43.8, 51.9] nmol/L if BMI < 25 kg/m2 and 38.1 [95%CI: 33.5, 42.7] nmol/L if BMI ≥25 kg/m2. Infant serum 25(OH)D concentrations at birth (r = 0.77; P < 0.0001) and 1 month (r = 0.59, P < 0.0001) were positively correlated with maternal postpartum serum 25(OH)D concentrations. Maternal serum 25(OH)D concentration was weakly correlated with maternal percent whole body fat mass (r = - 0.26, P = 0.002). Infants of mothers in I-OW/O had higher fat mass versus those of mothers in S-OW/O (914.0 [95%CI: 766.4, 1061.6] vs. 780.7 [95%CI: 659.3, 902.0] g; effect size [Hedges' g: 0.42]; P = 0.04 adjusting for covariates) with magnitude of difference of 220.4 g or ~ 28% difference.

CONCLUSIONS

Maternal and neonatal vitamin D status are positively correlated. In this study, maternal adiposity and serum 25(OH)D < 50 nmol/L are dual exposures for neonatal adiposity. These findings reinforce the importance of vitamin D supplementation early in infancy irrespective of vitamin D stores acquired in utero and maternal weight status.

Knowledge, attitude, performance, and determinant factors of Vitamin D deficiency prevention behaviours among Iranian pregnant women

BACKGROUND

Pregnancy is a high-risk period for vitamin D (Vit D) deficiency, and there is a direct relationship between Vit D deficiency during this period and maternal and fetal complications. Therefore, this study aimed to assess the knowledge, attitude, and practice of pregnant women concerning the adoption of behaviors to prevent Vit D deficiency and identify the determinant factors of such behaviors.

METHODS

In this cross-sectional study, 185 pregnant women with a mean age of 27.52 ± 5.9 years were selected from the Health Centers in Tabriz, Iran, using the stratified random sampling between 2018 September 23 and 2019 June 21. Data were collected using a researcher-made questionnaires comprising demographic information, knowledge, attitude, and practice of pregnant women towards Vit D deficiency. The chi-square test and Fisher's exact test were used to determine the relationship between the demographics of pregnant women and their knowledge and attitude. Moreover, the general linear model test was used to determine the predictors of performance. The p-value< 0.05 was considered to be significant in this study.

RESULTS

The findings showed that 85.6% of pregnant women were well aware of the importance and role of Vit D in pregnancy. In addition, 76.7 and 75% of the participants had good knowledge of getting enough Vit D from sunlight and preventing Vit D deficiency in pregnancy, respectively. Moreover, 91.7% of the pregnant women believed that Vit D has a vital role in maternal and fetal health, and 61.1% showed a high level of perceived self-efficiency in preventing Vit D deficiency. In addition, 67.2% of women regarded the unpleasant taste and price of Vit D rich foods, such as seafood, as barriers to get Vit D, and 91.7% mentioned the lack of public places specific to women and living in apartments as barriers to getting enough Vit D from sunlight. According to the results, 57.8 and 79.4% of pregnant women performed at a moderate level in getting Vit D from food and sunlight, respectively. In general, educational attainment (Pvalue = 0.02, B = 0.56), pregnancy age (Pvalue = 0.04, B = -0.26), parity (Pvalue = 0.03, B = -0.45), and perceived self-efficacy of mothers (Pvalue < 0.001, B = 0.340) were the determinant factors of getting Vit D from food and sunlight as behaviours to prevent Vit D deficiency in pregnancy.

CONCLUSION

The findings of the current study revealed that despite the good knowledge of women about the Vit D deficiency during pregnancy, their performance was moderate. The unpleasant taste and high price of seafood were barriers to using them, and the lack of public places specific to women and living in apartments, were barriers to using sunlight. The most important determinant of preventive behaviours was perceived self-efficacy. Developing an awareness program to promote best practices in pregnant women is essential to prevent vitamin D deficiency.

Determinants of circulating 25-hydroxyvitamin D concentration and its association with musculoskeletal health in midlife: Findings from the Hertfordshire Cohort Study

INTRODUCTION

Several studies have reported the importance of vitamin D status to musculoskeletal health in populations of older adults. Here we report relationships between circulating serum 25(OH)D and musculoskeletal health in a community cohort of UK adults in midlife and investigate whether environmental (dietary intake, use of supplements) and/or genetic factors (4 SNPs previously related to vitamin D status) play more significant roles in determining vitamin D status in this population.

METHODS

Participants were recruited from the Hertfordshire Cohort Study, an established longitudinal cohort study of community dwelling adults and were seen at baseline and follow up 9-12 years later. Lumbar spine and total femur BMD were measured at baseline using a Hologic QDR 4500 instrument. Osteoarthritis (OA) was defined by radiographs of the knees graded according to Kellgren & Lawrence at both time points. Serum 25(OH)D concentrations were measured using a DiaSorin Liaison chemiluminescent assay. Genotyping of 4 SNPs previously associated with 25(OH)D values were assessed: (rs12785878 (DHCR7), rs10741657 (CYP2R1) and rs6013897 (CYP24A1)) and a fourth SNP (rs4588), described as "a near-perfect proxy (i.e. substitute) for rs2282679 on the GC gene".

RESULTS

820 subjects (397 men, 423 women) participated at baseline, and 339 of these 820 subjects (164 men; 175 women) participated in a follow up study of OA progression. The median (IQR) age of participants at baseline was 64.0 (61.8-66.5) and 65.5 (63.3-67.6) for men and women respectively. Median circulating levels of 25(OH)D were 44.6 (35.0-63.0) nmol/L and 41.3 (29.8-53.5) nmol/L in men and women respectively. Circulating 25(OH)D was strongly associated with season of blood testing (p < 0.001). The greatest variance in a model of vitamin D status that included the four SNPs measured, season, and whether participants reported taking vitamin D supplements was explained by season of assay (17.9% men; 15.8% women). Higher femoral neck BMD was observed in men with higher baseline vitamin D status, after adjustment for age, season, BMI, smoker status, alcohol consumption, physical activity and social class (p = 0.01). Associations between 25(OH)D and BMD in women were not statistically significant in this population. There were no associations between circulating 25(OH)D and radiographic knee OA at either time point after adjustment for confounders and for duration of follow-up.

CONCLUSION

Circulating 25(OH)D levels were generally lower than is recommended in community dwelling adults in midlife, with marked seasonal variation observed, but relationships with reported vitamin D supplementation were weaker. Circulating 25(OH)D was directly associated with hip BMD in men but relationships with BMD in women and radiographic OA were not seen in this sample.

Vitamin D status and obesity markers in older adults: results from West China Health and Aging Trends study

Backgrounds

Vitamin D deficiency and insufficiency in older adults seems to be common, but the prevalence estimates are lacking in West China. Previous studies suggested that low vitamin D status was associated with obesity. However, most of them evaluated obesity based on body mass index (BMI) and there are no studies at present exploring the association between vitamin D status and different obesity markers. The present study aims to investigate the prevalence of low vitamin D status and evaluate the association between the vitamin D status and different obesity markers among older adults in West China.

Methods

Data was based on the baseline of West China Health and Aging Trends study (WCHAT). All of the participants were older than 60 years old in the present study. Vitamin D status was based on laboratory data, and obesity markers were assessed by bioelectrical impedance analysis (BIA) using the InBody 770 analyzer. Multiple linear regression was performed to find the association between the vitamin D status and various obesity markers.

Results

The study included 2661 individuals (mean age: 67.7 ± 6.0 years; males: 41 %). The mean vitamin D level was 18.8 ± 6.3 ng/ml (range: 5 to 59 ng/ml); 5.2 % of participants had a sufficient level of vitamin D, 31.8 % had vitamin D insufficiency, and 63.0 % had vitamin D deficiency. Our results showed that vitamin D status was negatively associated with fat mass index (FMI), visceral fat area (VFA), and waist-hip ratio (WHR) in both sexes. Comparing to other obesity markers, WHR had the strongest correlation with vitamin D status in both sexes (β = -6.090, P = 0.046 in males; β = -11.253, P < 0.001 in females). No significant association was found between vitamin D status and BMI in males.

Conclusion

The prevalence of vitamin D insufficiency and deficiency among older adults in West China was high. Among the older adults in west China, WHR showed stronger association with vitamin D status and was better for the prediction of vitamin D insufficiency or deficiency in both sexes, compared to BMI.

Trial registration

Chinese Clinical Trial Registry: ChiCTR1800018895.

Vitamin D and the risk for cancer: A molecular analysis

Uncontrolled overgrowth of cells, such as in cancer, is an unavoidable risk in life that affects nearly every second individual in industrialized countries. However, in part this risk can be controlled through lifestyle adjustments, such as the avoidance of smoking, unhealthy diet, obesity, physical inactivity and other cancer risk factors. A low vitaminD status is a risk in particular for cancers of colon, prostate, breast and leukocytes. VitaminD₃ is produced non-enzymatically, when the cholesterol precursor 7-dehydrocholesterol is exposed to UV-B from sunlight, i.e., all cholesterol synthesizing species, including humans, can make vitaminD₃. VitaminD endocrinology started some 550million years ago, when the metabolite 1α,25-dihydroxyvitaminD₃ and the transcription factor vitaminD receptor teamed up for regulating the expression of hundreds of target genes in a multitude of different tissues and cell types. Initially, these genes were focused on the control of energy homeostasis, which later also involved energy-demanding innate and adaptive immunity. Rapidly growing cells of the immune system as well as those of malignant tumors rely on comparable genes and pathways, some of which are modulated by vitaminD. Accordingly, vitaminD has anti-cancer effects both directly via controling the differentiation, proliferation and apoptosis of neoplastic cells as well as indirectly through regulating immune cells that belong to the microenvironment of malignant tumors. This review discusses effects of vitaminD on the epigenome and transcriptome of stromal and tumor cells, inter-individual variations in vitaminD responsiveness and their relation to the prevention and possible therapy of cancer.

Vitamin D status and vitamin D deficiency risk factors among pregnancy of Shanghai in China

Background

There is increasing awareness that vitamin D deficiency in pregnant women may be associated with several adverse effects for the mother and newborn. The risks for vitamin D deficiency are unclear. This study was to assess vitamin D nutritional status and vitamin D deficiency risk factors among pregnant women in Shanghai in China.

Methods

This study is a cross-sectional study conducted in the Sixth Affiliated People’s Hospital of Shanghai Jiao Tong University. A total of 953 healthy pregnant women participated, serological examinations and other variables included serum 25-hydroxyvitamin D [25(OH)D], total blood cholesterol (TCh), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) cholesterol, triglycerides at the first antenatal visit (12–14 weeks) pregnancy parity and age, body mass index (BMI) before pregnancy, and completed OGTTs test. Associations between vitamin D deficiency and possible predictors (age group, pre-pregnancy BMI, parity, and gestational hyperlipemia) were assessed with a multinomial logistic regression analysis. And also used to investigate the effects of 25(OH)D and the other variables on the occurrence of gestational diabetes mellitus.

Results

The mean vitamin D level of pregnancy was 16 (a range from 11 to 21) ng/ml, and severe vitamin D deficiency was 31.8% (303); vitamin D deficiency was 40.7% (388); vitamin D insufficiency was 25.1% (239); normal vitamin D was 2.4%(23). Vitamin D deficiency risk factors were age over 30, parity over 2, overweight, obese, and hyperlipemia. The increasing level of vitamin D nutritional status in pregnancy is significantly related to reducing gestational diabetes mellitus. Vitamin D deficiency is a risk factor for gestational diabetes mellitus.

Conclusions

It is a high prevalence of vitamin D deficiency in Chinese pregnancy in Shanghai. Aging more than 30 years, the parity of more than 2, overweight and obesity, and hyperlipemia are risk factors for vitamin D deficiency. Vitamin D deficiency is a risk factor for gestational diabetes mellitus. Public health strategies to prevent vitamin D deficiency should focus on those risks to promote health pregnancy of Shanghai in China.

Association between population vitamin D status and SARS-CoV-2 related serious-critical illness and deaths: An ecological integrative approach

BACKGROUND

Vitamin D population status may have possible unappreciated consequences to the coronavirus disease 2019 (COVID-19) pandemic. Α significant association between vitamin D sufficiency and reduction in clinical severity and inpatient mortality from COVID-19 disease has recently been shown, while a recent study has claimed lower COVID-19 cases in European countries with a better vitamin D status. Low serum 25-hydroxyvitamin-D [25(OH)D] was identified as an independent risk factor for COVID-19 infection and hospitalization, and administration of 0.532 mg (21280 IU) of calcifediol or 25(OH)D, followed by 0.266 mg on days 3 and 7 and then weekly until discharge or intensive care unit admission significantly reduced the need for intensive care unit treatment.

AIM

To elucidate the role of vitamin D European population status in the COVID-19 pandemic, data from the Worldometer were analyzed.

METHODS

Linear regression explored the correlation between published representative-standardized population vitamin D concentrations and the number of total cases/million (M), recovered/M, deaths/M and serious-critically ill/M from COVID-19 for 26 European countries populated > 4 M (Worldometer). Life expectancy was analyzed with semi-parametric regression. Weighted analysis of variance/analysis of covariance evaluated serious-critical/M and deaths/M by the vitamin D population status: Deficient < 50, insufficient: 50-62.5, mildly insufficient > 62.5-75 and sufficient > 75 nmol/L, while controlling for life expectancy for deaths/M. Statistical analyses were performed in XLSTAT LIFE SCIENCE and R (SemiPar Library).

RESULTS

Linear regression found no correlation between population vitamin D concentrations and the total cases-recovered/M, but negative correlations predicting a reduction of 47%-64%-80% in serious-critical illnesses/M and of 61%-82%-102.4% in deaths/M further enhanced when adapting for life expectancy by 133-177-221% if 25(OH)D concentrations reach 100-125-150 nmol/L, sustained on August 15, 2020, indicating a truthful association. Weighted analysis of variance was performed to evaluate serious-critical/M (r² = 0.22) by the vitamin D population status and analysis of covariance the deaths/M (r² = 0.629) controlling for life expectancy (r² = 0.47). Serious-critical showed a decreasing trend (P < 0.001) from population status deficient (P < 0.001) to insufficient by 9.2% (P < 0.001), to mildly insufficient by 47.6% (P < 0.044) and to sufficient by 100% (reference, P < 0.001). For deaths/M the respective decreasing trend (P < 0.001) was 62.9% from deficient (P < 0.001) to insufficient (P < 0.001), 65.15% to mildly insufficient (P < 0.001) and 78.8% to sufficient (P = 0.041).

CONCLUSION

Achieving serum 25(OH)D 100-150 nmol/L (40-60 ng/mL) (upper tolerable daily doses followed by maintenance proposed doses not requiring medical supervision, Endocrine Society) may protect from serious-critical illness/death from COVID-19 disease.

Vitamin D deficiency in children with acute bronchiolitis: a prospective cross-sectional case- control study

Background

25(OH) vitamin D levels are inversely associated with respiratory infections and childhood wheezing.

Objective

To evaluate serum 25(OH) vitamin D levels in infants and toddlers with acute bronchiolitis, compared to subjects with non-respiratory febrile illness.

Methods

A prospective cross-sectional case-control study which compared serum 25(OH) vitamin D levels between infants and toddlers diagnosed with acute bronchiolitis to subjects with non-respiratory febrile illness. Multivariate logistic regression, adjusted for age, sex, ethnicity and nutrition was performed. Correlation between serum vitamin D levels and bronchiolitis severity was assessed via Modified Tal Score and length of hospital stay (LOS).

Results

One hundred twenty-seven patients aged < 24 months were recruited; 80 diagnosed with acute bronchiolitis and 47 patients with non- respiratory febrile illnesses. Both groups had similar demographics aside from age (median [IQR] 5 [3–9] vs. 9 [5–16] months in the bronchiolitis group compared to control group (p = 0.002)). Serum 25(OH) vitamin D levels were significantly lower in the bronchiolitis group; median [IQR] 28[18–52] vs. 50[25–79] nmol/L, respectively, (p = 0.005). Deficient vitamin D levels (< 50 nmol/L) was found more frequently in the bronchiolitis group than controls; 73% vs. 51% (p = 0.028). Multivariate logistic regression showed vitamin D deficiency was more probable in bronchiolitis patients; OR [95% CI] 3.139[1.369–7.195]. No correlation was found between serum vitamin D levels and bronchiolitis severity, which was assessed via Modified Tal Score and by length of hospital stay.

Conclusion

Children with acute bronchiolitis displayed significantly lower vitamin D levels than children with non-respiratory acute febrile illnesses.

Vitamin D status and its longitudinal association with changes in patterns of sleep among middle-aged urban adults

OBJECTIVE

We examined relationships of vitamin D status with over time changes in patterns of sleep in a longitudinal study of Whites and African-American urban middle-aged adults, while further testing effect modification by age group, sex and race and the potential roles of dietary and supplemental vitamin D.

METHODS

Data on 1,760 middle-aged participants in the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS study: Age range at v₂: 33-71y, mean±SD:53.0±8.8, % women: 58.4%, % African-American:60.3%) were used, with complete baseline 25-hydroxyvitamin D [25(OH)D] serum concentration data, initial selected covariates and mediators, and initial and/or follow-up data on five sub-scales (sleep duration, daytime dysfunction, sleep disturbance, sleep latency and sleep quality) of the Pittsburgh Sleep Quality Index. Mean±SD time between initial and follow-up visits: 4.1±1.5 years. Time-interval multiple mixed-effects linear regression models were used.

RESULTS

Upon multiple testing adjustment, among Whites, initial 25(OH)D was associated with better sleep duration [25(OH)D × TIME γ±SE: -0.027±0.011, P=0.017] and sleep quality [25(OH)D × TIME γ±SE: -0.026±0.010, P=0.008] over time, with heterogeneity by race found for both relationships (P<0.05 for 25(OH)D × TIME × Race in the un-stratified model). These relationships remained unaltered after further adjustment for dietary and supplemental vitamin D, indicating that this association may be largely explained by sunlight exposure.

LIMITATIONS

Limitations included small sample size, selection bias, residual confounding and lack of objective sleep measures. Conclusions Vitamin D status, possibly through mechanisms involving sunlight exposure, was linked to a potential improvement in sleep duration and quality among White urban adults.

Low Vitamin D Status at Admission as a Risk Factor for Poor Survival in Hospitalized Patients With COVID-19: An Italian Retrospective Study

OBJECTIVE

Preliminary findings suggest a relationship between lower serum 25-hydroxyvitamin D [25(OH)D] levels and incidence and severity of COVID-19. The aim of this study was to evaluate the relationship between vitamin D status at admission and different markers of inflammation, coagulation, and sepsis in hospitalized patients with COVID-19.

METHOD

We conducted a retrospective study on 137 consecutive patients with SARS-CoV-2 infection and available data on serum 25(OH)D levels, who were admitted to our Institution between March 1 and April 30, 2020. Patients were divided into two groups: survivors (n = 78; 57%) and non-survivors (n = 59; 43%).

RESULTS

At admission, all patients showed hypovitaminosis D. Median total serum 25(OH)D levels at admission were significantly higher in survivors than non-survivors (12 ng/mL vs 8 ng/mL; p < 0.01). Non-survivors exhibited significantly higher median levels of white blood cell (WBC) count, neutrophil-to-lymphocyte count ratio (NLR), high-sensitivity C-reactive protein (hsCRP), ferritin, interleukin 6 (IL-6), D-dimer, fibrinogen, and procalcitonin (PCT) compared to survivors at three different time points during hospitalization. In a multivariate analysis performed by a logistic regression model, serum 25(OH)D levels were significantly inversely associated with risk of COVID-19-related in-hospital mortality (odds ratio, 0.91; 95% confidence interval, 0.85-0.98; p = 0.01). According to receiver operating characteristic curve analysis, hsCRP, NLR, ferritin, and D-dimer were the best predictive biomarkers for poor prognosis of COVID-19, whereas IL-6, PCT, fibrinogen, 25(OH)D, WBC count, and tumor necrosis factor alpha (TNF-α) may serve as supportive biomarkers for worse clinical course of the disease.

CONCLUSIONS

We found a markedly high prevalence (100%) of hypovitaminosis D in patients admitted to hospital with COVID-19, suggesting a possible role of low vitamin D status in increasing the risk of SARS-CoV-2 infection and subsequent hospitalization. The inverse association between serum 25(OH)D levels and risk of in-hospital mortality observed in our cohort suggests that a lower vitamin D status upon admission may represent a modifiable and independent risk factor for poor prognosis in COVID-19.

Vitamin D status, vitamin D intake, and sunlight exposure in adults adhering or not to periodic religious fasting for decades

We investigated whether periodic abstinence from foods of animal origin and a conservative lifestyle, with reduced sunlight exposure, affect vitamin D status. In a cross-sectional design, we measured the serum 25-hydroxyvitamin D concentration and assessed dietary vitamin D intake and sunlight exposure in 200 adults adhering to religious fasting for decades and in 200 non-fasters, with no differences between groups in bone mineral density. Fasters showed lower 25-hydroxyvitamin D concentration than non-fasters in winter and spring. Vitamin D intake and some indices of sunlight exposure (including two related to winter and spring) were lower in fasters, and 378 of the 400 participants exhibited vitamin D insufficiency or deficiency. In conclusion, individuals following a religious lifestyle had lower vitamin D intake, sunlight exposure and, at times, serum 25-hydroxyvitamin D concentration than controls, although these differences did not impact bone health.

Vitamin D status and associated factors among peri menopausal women in two selected districts of Kerala

Background

Vitamin D deficiency is highly prevalent among the Indian population and it is found to be associated with many diseases among perimenopausal women in various hospital-based studies.

Objectives

This study aimed to find out the Vitamin D status among perimenopausal women and to assess the association of selected factors with Vitamin D status among them.

Methods

A cross-sectional study was conducted among 184 perimenopausal women in two districts of Kerala from July 2018 to February 2019. The data were collected and blood sample was taken for determining the 25(OH) D levels after obtaining informed written consent. Descriptive and inferential statistics were done using SPSS version 22.

Results

Among the 184 women, 2 (1.1%) had sufficient, 18 (9.8%) had insufficient, and 164 (89.1%) had deficient 25(OH) D levels. The mean 25(OH) D levels among the population were 15.01 ± 4.32 ng/ml (95% confidence interval 14.38-15.63), much lower than the required level of 30 ng/ml. Vitamin D level was significantly higher among women who had exposure to sunlight, were on Vitamin D supplementation, and those who had skin diseases. 25(OH) D levels were higher among residents of Ernakulam district, older age group, low socioeconomic status, mixed-diet consumers, those who attained menopause, and those had calcium supplementation. The level was low among those who regularly use sunscreen topical applications and had other comorbidities such as hypothyroidism. However, none of these factors were significantly associated with 25(OH) D levels.

Conclusion

The study showed that Vitamin D deficiency is highly prevalent among the study population.

Is it reasonable to ignore vitamin D status for musculoskeletal health?

Severe vitamin D deficiency—25-hydroxyvitamin D (25OHD) concentrations below around 25–30 nmol/L—may lead to growth plate disorganization and mineralization abnormalities in children (rickets) and mineralization defects throughout the skeleton (osteomalacia) and proximal muscle weakness. Both problems are reversed with vitamin D treatment. Apart from this musculoskeletal dysfunction at very low vitamin D levels, there is apparent inconsistency in the available data about whether concentrations of 25OHD below around 50 nmol/L cause muscle function impairment and increase the risk of fracture. This narrative review provides evidence to support the contention that improving vitamin D status, up to around 50 nmol/L, plays a small causal role in optimizing bone and muscle function as well as reducing overall mortality.

Assessing the impact of a mushroom-derived food ingredient on vitamin D levels in healthy volunteers

BACKGROUND

Prevalence of vitamin D insufficiency/deficiency has been noted in athletic populations, although less is known about recreationally active individuals. Biofortification of natural food sources (e.g. UV radiated mushrooms) may support vitamin D status and is therefore of current scientific and commercial interest. The aim of this study was to assess the impact of a mushroom-derived food ingredient on vitamin D status in recreationally active, healthy volunteers.

METHODS

Twenty-eight participants were randomly assigned to either: 25 μg (1000 IU) encapsulated natural mushroom-derived vitamin D₂; matched-dose encapsulated vitamin D₃ or placebo (PL) for 12 weeks. Venous blood samples were collected at baseline, week 6 and 12 for analysis of serum 25(OH)D₂ and 25(OH)D₃ using liquid chromatography mass spectrometry. Habitual dietary intake and activity were monitored across the intervention.

RESULTS

Vitamin D status (25(OH)D_TOTAL) was significantly increased with vitamin D₃ supplementation from 46.1 ± 5.3 nmol·L^- 1 to 88.0 ± 8.6 nmol·L^- 1 (p < 0.0001) across the intervention, coupled with an expected rise in 25(OH)D₃ concentrations from 38.8 ± 5.2 nmol·L^- 1 to 82.0 ± 7.9 nmol·L^- 1 (p < 0.0001). In contrast, D₂ supplementation increased 25(OH)D₂ by + 347% (7.0 ± 1.1 nmol·L^- 1 to 31.4 ± 2.1 nmol·L^- 1, p < 0.0001), but resulted in a - 42% reduction in 25(OH)D₃ by week 6 (p = 0.001). A net + 14% increase in 25(OH)D_TOTAL was established with D₂ supplementation by week 12 (p > 0.05), which was not statistically different to D₃. Vitamin D status was maintained with PL, following an initial - 15% reduction by week 6 (p ≤ 0.046 compared to both supplement groups).

CONCLUSIONS

The use of a UV radiated mushroom food ingredient was effective in maintaining 25(OH)D_TOTAL in healthy, recreationally active volunteers. This may offer an adjunct strategy in supporting vitamin D intake. However, consistent with the literature, the use of vitamin D₃ supplementation likely offers benefits when acute elevation in vitamin D status is warranted.

Vitamin D status in children and adults in Sweden: dietary intake and 25-hydroxyvitamin D concentrations in children aged 10-12 years and adults aged 18-80 years

The study aimed to estimate vitamin D intake and plasma/serum 25-hydroxyvitamin D (25(OH)D) concentrations, investigate determinants of 25(OH)D concentrations and compare two 25(OH)D assays. We conducted two nationwide cross-sectional studies in Sweden with 206 school children aged 10-12 years and 1797 adults aged 18-80 years (n 268 provided blood samples). A web-based dietary record was used to assess dietary intake. Plasma/serum 25(OH)D was analysed by liquid chromatography-mass spectrometry (LC-MS) and immunoassay in adults and LC-MS/MS in children. Most participants reported a vitamin D intake below the average requirement (AR), 16 % of children and 33 % of adults met the AR (7⋅5 μg). In adults, plasma 25(OH)D below 30 and 50 nmol/l were found in 1 and 18 % of participants during the summer period and in 9 and 40 % of participants during the winter period, respectively. In children, serum 25(OH)D below 30 and 50 nmol/l were found in 5 and 42 % of participants (samples collected March-May), respectively. Higher 25(OH)D concentrations were associated with the summer season, vacations in sunny locations (adults), and dietary intake of vitamin D and use of vitamin D supplements, while lower concentrations were associated with a higher BMI and an origin outside of Europe. Concentrations of 25(OH)D were lower using the immunoassay than with the LC-MS assay, but associations with dietary factors and seasonal variability were similar. In conclusion, vitamin D intake was lower than the AR, especially in children. The 25(OH)D concentrations were low in many participants, but few participants had a concentration below 30 nmol/l.

Vitamin D in pregnancy: Where we are and where we should go

Vitamin D deficiency has been widely reported among pregnant women and infants around the world. Women with low sun exposure, high BMI, low vitamin D intakes and socioeconomic disadvantage with poor quality diets are at greatest risk of vitamin D deficiency, leading to very low serum concentrations of 25-hydroxyvitamin D (25(OH)D) in their offspring and an increased risk of nutritional rickets. Many observational studies, supported by compelling in vitro and in vivo data, have generated evidence suggesting that low vitamin D status in pregnancy may also contribute to the risk of adverse perinatal outcomes including hypertensive disorders (e.g., preeclampsia), fetal growth restriction, and preterm birth. However, the few large randomized controlled trials (RCTs) conducted to date have generated conflicting evidence for a role of vitamin D supplementation in improving perinatal outcomes. Vitamin D supplementation policies during pregnancy and implementation of policies vary within and between jurisdictions. Regulatory authorities have cited insufficient evidence to establish pregnancy-specific targets for serum 25(OH)D concentrations or prenatal vitamin D intake that effectively reduce the risks of adverse perinatal and infant outcomes. This paper arises from a Debate on Vitamin D Requirements during Pregnancy, held at the 22nd Vitamin D Workshop, 2019. From varied perspectives, our objectives were to evaluate the evidence for: vitamin D metabolism in pregnancy and the prevalence of gestational vitamin D deficiency worldwide; the translation of laboratory research findings to clinical studies on the role of vitamin D in perinatal health; the challenges of designing and conducting clinical trials to establish prenatal vitamin D requirements; and results to date of major large RCTs of prenatal vitamin D supplementation. Lastly, we explored potential next steps towards generating robust clinical data in this field to address both public health protection and patient care.

Is vitamin D status reflected by testosterone concentration in elite athletes?

Vitamin D is a nutrient whose active form affects tissues as a hormone and possibly enhances performance. One plausible mechanism is by increasing testosterone concentration, which is established as an important factor for athletic performance. Therefore the aim of the study was to examine the relationship between plasma concentration of 25(OH)D and testosterone in Polish elite track and field athletes depending on vitamin D status, season, training period, body composition, sex, type of training, sun exposure and vitamin D supplementation. Plasma concentrations of 25(OH)D and testosterone were measured in all seasons within two years in athletes (70 females, 79 males) who represent strength (n = 103) and endurance (n = 46) kinds of sports, in the preparatorycompetitive season and transition period. There were no differences in 25(OH)D concentration between male and female athletes, insufficiency [25(OH)D < 30 ng/ml] was observed in 32.9%, whereas deficiency [25(OH)D < 20 ng/ ml] in 3.2%. Circannual rhythm was noted for vitamin D but not for testosterone concentration; no correlations between them were found either in strength or endurance athletes or between 25(OH)D and body composition. Testosterone concentration was higher in the transition period than in the preparatory-competition period only in male athletes. Higher 25(OH)D was observed in athletes who trained during winter in Africa (higher sun exposure) or used oral supplementation, whereas the respective testosterone levels were unchanged. In athletes, testosterone concentration did not reflect vitamin D status. The widespread of inadequate vitamin D status among athletes, makes it vital to recommend them the regular monitoring of 25(OH)D concentration and use of reasonable supplementation.

Association of magnesium intake and vitamin D status with cognitive function in older adults: an analysis of US National Health and Nutrition Examination Survey (NHANES) 2011 to 2014

PURPOSE

Reduced cognitive function associated with aging has gained increasing attention as the US population ages. Magnesium plays a critical role in vitamin D biosynthesis and metabolism; and deficiencies in magnesium and vitamin D show associations with poor cognition. However, no study has examined their interaction. This study aimed to evaluate the associations of magnesium intake and serum 25-hydroxyvitamin D (25(OH)D) concentrations, indicating vitamin D status, with cognition, and interaction between these nutrients in older adults.

METHODS

Based on the National Health and Nutrition Survey (NHANES) 2011-2014, the study included 2466 participants aged ≥ 60 years who completed the Digit Symbol Substitution Test (DSST) and had data available on serum 25(OH)D and magnesium intake. Cognitive impairment was defined as a DSST score lower than the lowest quartile. Serum 25(OH)D concentrations were measured by HPLC-tandem mass spectrometry.

RESULTS

Higher total magnesium intake was independently associated with higher DSST scores (highest quartile vs lowest: β = 4.34, 95% CI 1.14-7.54). The association of total magnesium intake with high DSST score was primarily observed among women, non-Hispanic whites, physically active participants and those with sufficient vitamin D status, although the interactions were not significant. The odds of cognitive impairment was reduced with increasing intake of total magnesium (p trend < 0.01) and higher level of serum 25(OH)D (p trend = 0.05).

CONCLUSIONS

Findings suggest that high magnesium intake alone may improve cognitive function in older adults, and the association may be stronger among subjects with sufficient vitamin D status. Further studies are needed to confirm these findings.

Relationship between vitamin D status in the first trimester of pregnancy and gestational diabetes mellitus - A nested case-control study

BACKGROUND & AIMS

Gestational diabetes mellitus (GDM) is one of the most frequent medical complications during pregnancy. It has been associated with many adverse pregnancy, fetal and neonatal outcomes, as well as with an increased risk for mothers and children in the long term. There is a growing interest in vitamin D and its potential role in the development of metabolic disorders. However, the medical literature is not consensual. The aim of this study was to assess the risk of GDM according to vitamin D status during the first trimester.

METHODS

This study is a nested case-control study performed from a multicenter prospective observational cohort of pregnant women assessed for 25-hydroxyvitamin D levels (25OHD). Three hundred ninety-three patients were included in the initial cohort. After applying exclusion criteria, a total of 1191 pregnant women were included. Two hundred fifty women with GDM (cases) were matched to 941 women without GDM (controls) for parity, age, body mass index before pregnancy, the season of conception, and phototype. This study was funded by a grant from the "Programme Hospitalier de Recherche Publique 2010".

RESULTS

The GDM risk was significantly greater for patients with 25OHD levels <20 ng/mL (OR = 1∙42, 95% CI 1∙06-1∙91; p = 0∙021). However, there was no significant relationship with other thresholds. The study of 25OHD levels with the more precise cutting of 5 units intervals showed a variable relationship with GDM risk, as the risk was low for very low 25OHD levels, increased for moderated levels, decreased for normal levels, and finally increased for higher levels.

CONCLUSION

According to our study, there seems to be no linear relationship between GDM and 25OHD levels in the first trimester of pregnancy since GDM risk does not continuously decrease as 25OHD concentrations increase. Our results most probably highlight the absence of an association between 25OHD levels and GDM risk.

Nutritional rickets: Historic overview and plan for worldwide eradication

Rickets was first described in great detail in the mid 17th century and was affecting a great number of children in major European cities. The disease, however, existed already in the Roman times. The etiology of this disease remained enigmatic until the 1920s when two different mechanisms, lack of exposure to sunlight and lack of a dietary factor were finally solved by the discovery of vitamin D and its dual origin. Soon thereafter, the implementation of vitamin D supplementation for all infants and small children largely eliminated nutritional rickets in Europe and North America. It took nearly a century to elucidate the complex chemistry, metabolism, mode and spectrum of activity of the vitamin D endocrine system. Nutritional rickets, whether due to simple vitamin D or calcium deficiency or both, remains widely ravaging many infants and children around the world. Asian countries and the Middle East are mainly confronted with vitamin D deficiency whereas many African and some Asian countries face calcium deficiency rickets. Immigrants and refugees or in general people with a darker skin living in moderate climate zone are also confronted with this disease. There is great consensus how this disease could be prevented or cured. In collaboration with most international professional societies, we prepare a memorandum, in line with the successful battle against iodine deficiency disorders, to convince the World Health Organization and its member states to start an implementation program to eradicate nutritional rickets by 2030.

Prevalence and determinants of vitamin D deficiency and insufficiency among three immigrant groups in Finland: evidence from a population-based study using standardised 25-hydroxyvitamin D data

OBJECTIVE

We investigated the determinants of serum 25-hydroxyvitamin D [S-25(OH)D] and dietary vitamin D sources among three immigrant groups in Finland and compared their S-25(OH)D to the general Finnish population.

DESIGN

Cross-sectional population-based Migrant Health and Wellbeing Study and the nationally representative Finnish Health 2011 Survey. S-25(OH)D was standardised according to the Vitamin D Standardisation Program. Vitamin D sources were assessed by interview.

SETTING

Six different municipalities in Finland (60°-63°N).

PARTICIPANTS

Immigrants aged 18-64 years (446 Russians, 346 Somalis, 500 Kurds), 798 Finns aged 30-64 years.

RESULTS

The mean of S-25(OH)D was 64 (95 % CI 62, 66), 44 (95 % CI 41, 46), 35 (95 % CI 34, 37) and 64 (95 % CI 62, 66) nmol/l for Russians, Somalis, Kurds and Finns, respectively. S-25(OH)D among Somalis and Kurds was lower compared with Finns (P < 0·001). The prevalence of vitamin D deficiency (S-25(OH)D <30 nmol/l) and insufficiency (S-25(OH)D <50 nmol/l) was higher among immigrants than Finns (P < 0·001). Vitamin D-rich foods differed between the groups; vitamin D-fortified fat spread consumption was higher among Somalis (91 %) than among Russians (73 %) and Kurds (60 %); fish was less consumed among Kurds (17 %) than among Russians (43 %) and Somalis (38 %); and 57 % Russians, 56 % Kurds and 36 % Somalis consumed vitamin D-fortified dairy daily (P < 0·001 for all). Daily smoking, alcohol consumption and winter blood sampling were determinants of vitamin D insufficiency (P ≤ 0·03). Older age, physical activity, fish and vitamin D-fortified dairy consumption were associated with lower odds of insufficiency (P ≤ 0·04).

CONCLUSIONS

Vitamin D status differed among immigrant groups and the determinants are, to some degree, associated with learned or existing cultural behaviours.

Diagnosis and management of vitamin D deficiency in the Gulf Cooperative Council (GCC) countries: an expert consensus summary statement from the GCC vitamin D advisory board

OBJECTIVE

A summary of recommendations is given within the Gulf Cooperation Council (GCC) setting on the assessment and management of vitamin D deficiency in the region.

METHODS

An assembly of 11 regional experts gathered to formulate an all-inclusive approach to vitamin D deficiency within GCC.

RESULTS AND CONCLUSION

Several gaps were identified before regional guidelines could be developed. These include adequacy and standardization of vitamin D testing, frequency of repeated testing and reference ranges, distinguishing prevention from the treatment of vitamin D deficiency, quality assurance of vitamin D products sold within GCC including contents and origins of products, and cut-points for vitamin D levels in local populations. A platform is created that can be further developed for overall regional implementation.

The Association of Vitamin D Status with Lipid Profile and Inflammation Biomarkers in Healthy Adolescents

Background: The association between vitamin D status and inflammatory biomarkers and lipid profile is not well known, especially in adolescents. Therefore, the aim of the current study is to investigate the association of vitamin D status with serum lipids and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, in male adolescents. Methods and materials: A sample of seventy-one high school male students, aged 17 years old, from a high school in Tehran were enrolled in the study. They were divided into four groups including group with serum vitamin D below 25 (ng/mL) (SVD < 25; n = 36), 25 and above (ng/mL) (SVD ≥ 25; n = 35), negative-hsCRP (n = 48), and positive-hsCRP (n = 23). Weight, height, body mass index, dietary intake, serum lipids, and inflammatory biomarkers, including IL-10, IL-6, hsCRP, and TNFR-2, were measured. Results: In the (SVD < 25) group, the serum level of TNFR-2 was significantly higher compared to that in the (SVD ≥ 25) group. There was a significant negative association between serum TNFR-2 and vitamin D levels in the whole sample. We found significant lower levels of IL-10 in positive-hsCRP group compared to the negative-hsCRP group. In addition, there was a significant negative correlation between the serum vitamin D level and hsCRP in both hsCRP groups. The HDL level was lower in the (SVD < 25) group compared to that in the (SVD ≥ 25) group. Finally, there was a negative correlation between the serum HDL and hsCRP levels in the positive-hsCRP subjects. Conclusion: Based on the findings it can be concluded that serum vitamin D affects HDL and inflammation status. Although serum levels of HDL and inflammation status are both predictors of metabolic syndrome and cardiovascular disease, further studies are needed to prove it, especially in adolescents.

Impact of vitamin D supplementation model on the circulating levels of 25 (OH) D in Algerian children aged 1-23 months

Vitamin D deficiency is a public health problem around the world. In Algeria, the nutritional situation is still subject to uncertainties. In order to evaluate the vitamin D status and to know the impact of the current vitamin D supplementation model on the circulating levels of 25 (OH) D, an investigation was conducted on a group of Algerian children. The study was conducted in the Blida region (Northern Algeria). Sampling focused on 150 healthy children, aged between 1 and 23 months old, recruited from Ben Boulaïd hospital pediatric ward. 83% of children (n = 125) have been supplemented with vitamin D (D3 B.O.N®) according to a scheme currently designed in Algeria (the first intake of 200 000 IU at 1 month and the second intake of 200 000 IU at 6 months). 17% of children (n = 25) have escaped from a supplementation. The average values of 25(OH) D are respectively: 51 ± 20 μg/L for 103 supplement children with vitamin D (25 (OH)D ≤ 100 μg/L), 222 ± 106 μg/L for 22 supplement children with vitamin D (25(OH) D > 100 μg/L) and 30 ± 16 μg/L for 25 non-supplement children with vitamin D. The prevalence of vitamin D deficiency is lower (4%) among the children group with vitamin D supplement. These results show that the vitamin D supplementation model seems entirely efficient on the improvement of vitamin D status.

Vitamin D Status in a Population of Well Children: Amasya Sample

OBJECTIVE

The aim of this study was to determine the vitamin D status of children living in Amasya, a city in northern Turkey. Vitamin D is an essential hormone for the health of the musculoskeletal system and acts as a modulator for the immune system, a protector of the cardiovascular system and a regulator of metabolic homeostasis.

METHODS

A total of 2551 healthy individuals aged 1 to17 years enrolled in this study. They were divided into 4 groups, according to their ages. Vitamin D status was classified based on the 2015 global consensus statement from the Endocrine Society. The data were collected from the hospital record system, retrospectively, and categorized according to age, gender, and the season in which the blood sample was taken for the measurement of 25 (OH) D levels.

RESULTS

Only 39% of the subjects were found to have sufficient vitamin D levels (>50 nmol/l [i.e., >20 ng/ml]), while the rest had poor vitamin D status. The insufficiency and deficiency problems were greater in females especially in winter and increasing with age.

CONCLUSION

The high frequency of poor vitamin D status in otherwise healthy children indicates a necessity for supplementation and for implementing lifelong strategies that increase and maintain adequate levels of sun exposure.

Type 2 Diabetes Mellitus, Insulin Resistance, and Vitamin D

PURPOSE OF REVIEW

There is a growing, largely inconsistent, literature on the role of vitamin D in association with type 2 diabetes, insulin resistance/insulin secretion, glycemic indices, and complications of type 2 diabetes. Pathophysiologic, bystander, preventive, and treatment roles of vitamin D have all been proposed. In this focused review, we attempt to organize and clarify our current information in this area.

RECENT FINDINGS

Clinical study interpretation is difficult because of variability in dosage, dosage form, study duration, and populations studied, as well as recently reported normal human polymorphisms in vitamin D synthesis and catabolism, vitamin D-binding protein, and vitamin D receptors in addition to a host of potential epigenetic confounders. Low vitamin D status appears to be associated with type 2 diabetes and most other insulin resistance disorders reported to date. The extraskeletal benefits of supplementation/repletion in these disorders in our species, with a few highlighted exceptions, remain to be established. This focused review attempts to summarize our current knowledge in this burgeoning area through a review of key meta-analyses, observational studies, randomized control trials, and Mendelian randomization studies and will hopefully serve as a guide to indicate future research directions and current best practice.

Vitamin D as an Adjuvant Therapy in Neonatal Hypoxia: Is it Beneficial?

Background

Neonatal hypoxic ischemic encephalopathy (HIE) is a potentially devastating disorder associated with significant mortality and long-term morbidity.

Objective

The aim of this study was to study the role of vitamin D as an adjuvant therapy for management of neonatal HIE.

Patients and Methods

This study was carried out on 60 neonates with HIE grade II who were diagnosed according to modified Sarnat staging and were divided in to 2 groups: Group I: Included 30 neonates with Sarnat grade II HIE who received single daily oral dose of vitamin D3 (1000 IU) for 2 weeks in addition to daily subcutaneous (SC) human recombinant erythropoietin (2500 IU/kg) for 5 days and IM or IV magnesium sulphate 250 mg/kg within half an hour of birth, and subsequently 125 mg/kg at 24 and 48 hours of life. Group II: Included 30 neonates with HIE grade II who received erythropoietin and magnesium sulphate as group I but without vitamin D. Two blood samples were taken from all neonates included in both groups; the 1^st at diagnosis and the 2^nd after 2 weeks of therapy. This study included also 30 healthy neonates as a control group. All neonates included in this study were subjected to: complete clinical examination with assessment of Apgar score at 5 and 10 minutes, measurement of arterial blood gases and serum 25 (OH) vitamin D, calcium, phosphorus, S100-B and IL-17 levels.

Results

Before therapy, there were no significant differences between group I and II in PH, PO2 and PCO2 (p= 0.294, 0.462, 0.758 respectively), but after 2 weeks of therapy, there were significantly higher PH levels in group I compared with group II (p <0.001) while there were no significant differences between group I and II regarding PO2 and PCO2. Before therapy, there were no significant differences in serum 25(OH) vitamin D levels between group I and II while there were significantly lower serum 25(OH) vitamin D levels in group I and II compared with controls (P1; comparison between group I and II = 0.742, P2; comparison between group I and controls = 0.001 and P3; comparison between group II and controls = 0. 001). There were no significant differences between group I and II and between group I and II and control as regard serum calcium (P1= 0.943, P2= 0.875 and P3= 0.764) and phosphorus (P1= 0.862, P2= 0.921, P3= 0.786). There were no significant differences between group I and II regarding serum IL-17 levels while there were significantly lower serum IL-17 levels in group I and II compared with controls (P1 = 0.457, P2 = 0.043 and P3 = 0.023). Before therapy, there were no significant differences in serum S100-B levels between group I and II while there were significantly higher serum S100-B levels in group I and II compared with control (P1 = 0.381, P2 = 0.001 and P3= 0.001) but after therapy, there were significantly higher S100-B levels in group II compared with group I and significantly higher S100-B levels in group I and II compared with control (P1= 0.001, P2= 0.043, P3 = 0.001). There were significant negative correlations in group I between serum S100-B and PH and between S100-B and serum vitamin D before and after therapy.

Conclusion

Vitamin D was found to improve the cases of group I as demonstrated by the reduction of serum S100-B levels after vitamin D therapy.

Recommendations

Extensive multicenter studies are required on a large number of patients with Sarnat grade II HIE with longer duration of follow up to give valid recommendations about the use of vitamin D as an adjuvant therapy in Sarnat grade II HIE.

Infection Status of Rural Schoolchildren and its Relationship with Vitamin D Concentrations

OBJECTIVES

To assess the nutritional and infection status of rural schoolchildren and to study the relationship of infection status with serum 25(OH)D concentrations.

METHODS

This study was carried out in a primary school, in a rural setting, near Pune (18°N), Maharashtra. Data collected from 387 children included anthropometric, clinical, infection-related data (using a validated questionnaire) and dietary data (by 24-h recall method over 3 non-consecutive days, including a holiday) and serum 25(OH)D estimations (by ELISA).

RESULTS

Prevalence of underweight and stunting were 18% and 11% respectively. Upper respiratory tract infection (URTI) related symptoms were commonly reported. Episodes of URTI were found to be significantly and negatively correlated with serum 25(OH)D concentrations (r_s = -0.14, p < 0.05) and lesser URTI episodes and duration were reported by children who were vitamin D sufficient as compared to those who were insufficient. No association of total infections was found with vitamin D status.

CONCLUSIONS

Moderate prevalence of underweight and stunting and frequent URTIs were observed in this population. Higher serum 25(OH)D concentrations and vitamin D sufficiency may be important for prevention of upper respiratory tract infections in rural children.

Role of Vitamin D Status in Diabetic Patients with Renal Disease

Diabetes mellitus (DM) poses a major public health problem worldwide, with ever-increasing incidence and prevalence in recent years. The Institute for Alternative Futures (IAF) expects that the total number of people with type 1 and type 2 DM in the United States will increase by 54%, from 19,629,000 to 54,913,000 people, between 2015 and 2030. Diabetic Nephropathy (DN) affects about one-third of patients with DM and currently ranks as the first cause of end-stage kidney disease in the Western world. The complexity of interactions of Vitamin D is directly related with progressive long-term changes implicated in the worsening of renal function. These changes result in a dysregulation of the vitamin D-dependent pathways. Various studies demonstrated a pivotal role of Vitamin D supplementation in regression of albuminuria and glomerulosclerosis, contrasting the increase of glomerular basement membrane thickening and podocyte effacement, with better renal and cardiovascular outcomes. The homeostasis and regulation of the nephron’s function are absolutely dependent from the cross-talk between endothelium and podocytes. Even if growing evidence proves that vitamin D may have antiproteinuric, anti-inflammatory and renoprotective effects in patients with DN, it is still worth investigating these aspects with both more in vitro studies and randomized controlled trials in larger patient series and with adequate follow-up to confirm the effects of long-term vitamin D analogue supplementation in DN and to evaluate the effectiveness of this therapy and the appropriate dosage.

Vitamin D status in under five children in diverse communities of Karachi

Background & Objective:

Vitamin D deficiency (VDD) prevalence is very high in pediatric population in developing countries including Pakistan. VDD contribute significantly to morbidity and mortality among children under five years. Therefore, it is vital to study vitamin D levels in population for future interventions and disease control. Our objective was to determine 25(OH)D levels in children of one to 59 months of age in socio-economically diverse communities of Karachi, Pakistan.

Methods:

The cross- sectional analytical survey was carried out over 6 months from January -June 2017. Following proportionate sampling technique four clusters were randomly selected from Korangi, Saddar, Sindhi para and Manzoor colony, Karachi. Blood samples for 25(OH)D and zinc levels were carried out using ELISA and colorimetry. VD level <20 ng/ml was defined as VDD and serum zinc <65ug/dl as low zinc levels. Data including area of residency, gender, ethnicity, parent’s education, family income, house status, duration of sun exposure and history of VD and zinc intake in last 3 months was collected from parents / care seekers on pretested and pre-coded semi-structured questionnaire. Data was analyzed using SPSS version-20. Frequencies and percentages were computed for categorical variables like gender, type of malnutrition whereas mean with standard deviation was used for VD and zinc levels and vitamin D status was compared in three different residential categories according to nutritional status.

Results:

Out of 120 children, 67 (56%) were boys and 53 (44%) girls. Mean VD level was 22.8±14.8 ng/ml. Around 60% (70) children were VD deficient, whereas 15 % (18) had insufficient 25(OH)D levels. VDD was more prevalent among low socio-economic group with no obvious difference in age category. Mean zinc level was 123.8±47.45 ug/dl and it was either normal or high (42%) rather than low. Malnutrition was observed in 65% children and majority (82%) of them were undernourished. Optimal sun exposure was reported in 24% children only.

Conclusion:

Vitamin D deficiency was highly prevalent in our study population. Children of low socio-economic strata and with sub-optimal sun light exposure are at high risk of vitamin D deficiency. Unexpectedly, high zinc levels in majority of our children with low VD status needs further evidence to substantiate this inverse relation.

Association between 25-OH-vitamin D and C-reactive protein as a marker of inflammation and cardiovascular risk in clinical practice

Background

C-reactive protein is an acute phase response marker and, in an epidemiological context, a predictor of cardiovascular risk. 25-Hydroxy-vitamin D is the best indicator for vitamin D status, but it can be altered by the presence of acute phase response. Our aim was to evaluate the association between serum concentrations of 25-hydroxy-vitamin D and C-reactive protein to assist the interpretation of vitamin D status in a clinical context.

Methods

We evaluated retrospectively 5076 patients ( n = 4087 women) assessed for 25-hydroxy-vitamin D and C-reactive protein simultaneously. Subjects were classified according to the origin as hospitalized patients ( n = 410) and outpatients ( n = 4666). Outpatients included patients from specialized ( n = 3943) and primary ( n = 723) care. Serum 25-hydroxy-vitamin D was determined by using liquid chromatography and serum C-reactive protein by using immunoturbidimetry.

Results

Concentrations of 25-hydroxy-vitamin D and C-reactive protein were significantly different between hospitalized subjects and outpatients but not for specialized and primary care settings. Serum concentrations of 25-hydroxy-vitamin D decreased as C-reactive protein increased. Hospitalized patients with C-reactive protein concentrations >30 mg/L showed a significant reduction of 25-hydroxy-vitamin D. In outpatients with C-reactive protein within the reference range (≤10 mg/L), C-reactive protein concentrations were not significantly different for serum 25-hydroxy-vitamin D concentrations >37.5 nmol/L.

Conclusions

Our data question the reliability and usefulness of assessing 25-hydroxy-vitamin D status as a biomarker of nutritional status in patients displaying acute phase response, especially at concentrations of C-reactive protein >30 mg/L. In addition, the present study shows that in subjects displaying C-reactive protein values within the reference range, serum concentrations of 25-hydroxy-vitamin D >37.5 nmol/L were not associated with lower concentrations of cardiovascular risk (as assessed by C-reactive protein concentrations).

Determinants of vitamin D status of healthy office workers in Sydney, Australia

Low vitamin D status, measured as 25-hydroxyvitamin D (25OHD), has been linked to increased risk of osteoporosis and other disorders. Due to the indoor nature of office work, there may be an increased risk of 25OHD deficiency in this group. The aim of the current study was to evaluate seasonal variations of 25OHD in a population of healthy office workers, and to assess the effect of sun exposure behaviour, skin pigmentation, physical activity (PA) and dietary intake on serum 25OHD concentrations. We assessed the vitamin D status of healthy office workers in Sydney, Australia, at the end of summer (n = 103) and then at the end of winter (n = 71). Data on anthropometry, PA, dietary intake, sun exposure and skin phototype were collected along with blood samples. Serum 25OHD was measured by radioimmunoassay. Mean 25OHD concentration in late summer was 68 ± 27 nmol/L (range: 24-160 nmol/L), and in late winter was 59 ± 32 nmol/L (range: 15-174 nmol/L). 25OHD deficiency (<50 nmol/L) was observed in 29% and 42% of participants at end-summer and end-winter, respectively. Almost 10% of individuals were extremely deficient (<25 nmol/L) at end-winter, particularly those with dark skin (phototypes 5 and 6). Independent predictors of end-summer 25OHD were skin phototype (p < 0.02), summer sun exposure (p < 0.001) and skin area exposed (p = 0.005). The strongest predictor of end-winter 25OHD was end-summer 25OHD concentration (p < 0.001). If this was excluded from the model, the independent predictors of end-winter 25OHD were skin phototype (p < 0.01), sun exposure in winter (p = 0.01) and oily fish consumption (p < 0.05). Sunscreen use was significantly associated with higher vitamin D status (p < 0.05) as those who used sunscreen were also more likely to spend time outdoors. We conclude that sun exposure is beneficial for vitamin D status even with sunscreen use. Vitamin D supplements should be targeted to individuals who are darker skinned or unable to obtain adequate sun exposure, particularly during the winter months.

Vitamin D status in a multi-ethnic population of northern Norway: the SAMINOR 2 Clinical Survey

Objective

To investigate serum 25-hydroxyvitamin D (S-25(OH)D) concentration in a multi-ethnic population of northern Norway and determine predictors of S-25(OH)D, including Sami ethnicity.

Design

Cross-sectional data from the second survey of the Population-based Study on Health and Living Conditions in Regions with Sami and Norwegian Populations (the SAMINOR 2 Clinical Survey, 2012–2014). S-25(OH)D was measured by the IDS-iSYS 25-Hydroxy Vitamin Dˢ assay. Daily dietary intake was assessed using an FFQ. BMI was calculated using weight and height measurements.

Setting

Ten municipalities of northern Norway (latitude 68°–70°N).

Participants

Males (n 2041) and females (n 2424) aged 40–69 years.

Results

Mean S-25(OH)D in the study sample was 64·0 nmol/l and median vitamin D intake was 10·3 µg/d. The prevalence of S-25(OH)D<30 nmol/l was 1·9 % and <50 nmol/l was 24·7 %. In sex-specific multivariable linear regression models, older age, blood sample collection in September–October, solarium use, sunbathing holiday, higher alcohol intake (in females), use of cod-liver oil/fish oil supplements, use of vitamin/mineral supplements and higher intakes of vitamin D were significantly associated with higher S-25(OH)D, whereas being a current smoker and obesity were associated with lower S-25(OH)D. These factors explained 21–23 % of the variation in S-25(OH)D.

Conclusions

There were many modifiable risk factors related to S-25(OH)D, however no clear ethnic differences were found. Even in winter, the low prevalence of vitamin D deficiency found among participants with non-Sami, multi-ethnic Sami and Sami self-perceived ethnicity was likely due to adequate vitamin D intake.

Selenomethionine potentiates the impact of vitamin D on thyroid autoimmunity in euthyroid women with Hashimoto's thyroiditis and low vitamin D status

BACKGROUND

Both exogenous vitamin D and selenium reduce thyroid antibody titers. The aim of the study was to investigate whether the impact of vitamin D on thyroid autoimmunity is affected by selenium intake.

METHODS

The study included 47 euthyroid women with Hashimoto's thyroiditis and low vitamin D status, 23 of whom had been treated with selenomethionine (200 μg daily) for at least 12 months before the beginning of the study. During the study, all patients were treated with vitamin D preparations (4000 IU daily). Serum titers of thyroid peroxidase and thyroglobulin antibodies, as well as circulating levels of thyrotropin, free thyroid hormones and 25-hydroxyvitamin D were measured before vitamin D supplementation and 6 months later. Moreover, at the beginning and at the end of the study, we calculated Jostel's thyrotropin index, the SPINA-GT index and the SPINA-GD index.

RESULTS

With the exception of the free triiodothyronine/free thyroxine ratio and the SPINA-GD index, there were no differences between the study groups. In both groups, vitamin D increased 25-hydroxyvitamin D levels, reduced thyroid peroxidase and thyroglobulin antibody titers, as well as increased the SPINA-GT index. The effects on antibody titers and the SPINA-GT index were more pronounced in women receiving selenomethionine. Neither in selenomethionine-treated nor in selenomethionine-naïve women vitamin D affected serum hormone levels, Jostel's index and the SPINA-GD index.

CONCLUSIONS

The results of the study suggest that selenium intake enhances the effect of vitamin D on thyroid autoimmunity.

Maternal risk factors and newborn infant vitamin D status: a scoping literature review

Low vitamin D (VitD) status is common among newborn infants, more so in temperate latitudes with evidence that maternal VitD deficiency is a major risk factor given that the neonate relies solely on maternal-fetal transfer of VitD. This scoping review was conducted to provide an overview of the latest evidence from studies regarding the impact of maternal risk factors on infant 25-hydryoxyvitamin D [25(OH)D] concentrations with a focus on studies in Canada and the United States. Several maternal risk factors that contribute to low maternal-fetal 25(OH)D concentrations have been reported over many decades, but no clear pattern has been established for multiethnic populations. For example, darker skin pigmentation and ethnicity are common risk factors for low VitD status. Studies in predominantly white women showed that supplementation of VitD during pregnancy causes significant increases in maternal serum 25(OH)D which often improves cord serum 25(OH)D values. In addition, VitD recommendations by health care professionals and adherence to supplementation by pregnant women appear to positively influence maternal and infant 25(OH)D concentrations. Conversely, winter season, obesity, lower socioeconomic status including lifestyle factors (smoking), and use of medication pose risk for lower maternal-fetal transfer of VitD. However, there is still a dearth of pertinent data on the relationship between some of the maternal risk factors and newborn 25(OH)D concentrations, for instance, relationships between gestational diabetes and neonatal VitD status. Additional research is required to determine if the same target for 25(OH)D concentrations applies for pregnant women, neonates, and infants.

Determinants of vitamin D status in physically active elderly in the Netherlands

Purpose

Vitamin D deficiencies are common in elderly, which increases the risk for, e.g., bone fractures. Identification of determinants of vitamin D status may provide leads for specific deficiency prevention strategies. Although determinants of vitamin D status have been studied in various populations, this has not been examined in elderly that have a physically active lifestyle.

Methods

Vitamin D status of 450 physically active elderly who do not use vitamin D supplements was determined and information on possible determinants (demographic, dietary intake and physical activity) was collected around a prolonged four day walking event in July and analyzed in linear regression models.

Results

The average summertime serum 25(OH)D concentration was 88.8 ± 22.4 nmol/L. Only 2% of the participants had a 25(OH)D concentration below 50 nmol/L. Dietary intake of vitamin D was 4.0 ± 1.9 µg/day, and the participants spent 12.4 ± 8.6 h/week on outdoor activities. In the multivariate model, lower age (= − 0.48, 95% CI − 0.80 to − 0.16), lower BMI (= − 0.86, 95% CI − 1.62 to − 0.10), being a moderate to high drinker versus a non-drinker (= 7.97, 95% CI 0.43–15.51) and more outdoor physical activity (= 0.25, 95% CI 0.01–0.50) were significantly associated with higher 25(OH)D concentrations.

Conclusions

In physically active elderly, vitamin D status was very high in summertime, with few deficiencies, suggesting that elderly with a physical active lifestyle might not necessarily need supplements during the summer period. Lower age, lower BMI, higher alcohol intake and more outdoor physical activity had a significant association with vitamin D status.

Associations of vitamin D status and metabolic dyslipidemia and hypertriglyceridemic waist phenotype in apparently healthy adults

BACKGROUND

Recent studies have shown that Vitamin D deficiency is very common globally. Vitamin D deficiency is associated with lipid metabolism. A relationship between vitamin D levels and waist circumference (WC) has been observed. The purpose of this study is to evaluate the relationship between vitamin D status and metabolic dyslipidemia and the hypertriglyceridemic waist phenotype.

METHODS

This cross-sectional study was conducted on 265 healthy Tehran adults. Hypertriglyceridemic waist phenotype (HTGWP) was described as serum triacylglycerol concentrations >150 mg/dL and concurrent WC > 88 cm (women) and >102 cm (men). Dyslipidemia was defined as: 1) TG level of >150 mg/dL 2) HDL > 40 mg/dL for men or >50 mg/dL for women, as has been previously described.

RESULTS

Current study's results demonstrated that HTGWP was significantly associated with weight, age, WC, hip, fat percent, TG, lipid profile, ALT and BMI. We found 77% reduction in the chances of developing metabolic dyslipidemia in suficient satus of vitamin D in compare to deficiency, although the significancy was mariginal, OR: 0.33, 95% CI of 0.09 to 1.21, P = 0.09. However, our results revealed that vitamin D deficiency, compared with normal status, can increase the risk of phenotype 1 (high TG/high WC); OR: 3.86 and 95% CI from 0.86 to 0.99, p for trend = 0.05.

CONCLUSIONS

Significant associations were found between vitamin D status and HTGWP. In addition, there was a relationship between vitamin D and lipid profiles. There is a direct correlation between TG and waist circumference in insulin resistance in healthy Tehran adults.