Seasonal variations in serum 25-hydroxy vitamin D levels in a Swedish cohort

Tapping natures rhythm: the role of season in mitochondrial function and genetics in the UK biobank

BACKGROUND

Mitochondria are small organelles inside our cells crucial for producing energy and heat, cell signaling, production and degradation of important molecules, as well as cell death. The number of mitochondria in each cell is a marker for mitochondrial function, which generally declines with increasing age. However, we found that there is also a considerable seasonal variation of mitochondrial abundance, which warrants further research.

METHODS

We leveraged data from individuals participating in the UK Biobank study and computed their mitochondrial abundance from Exome sequencing reads mapping to the mitochondrial genome. The seasonal effect was modelled as a sine-cosine function across the year and changes in amplitude, acrophase and displacement of mitochondrial abundance due to various demographic, lifestyle, genetic, proteomic, and metabolomic markers were investigated with multivariate regression.

RESULTS

We found that mitochondrial DNA (mtDNA) abundance was higher in winter than in summer. This difference is related to advanced age, a higher BMI and smoking behavior which resulted in a reduced amplitude of mtDNA abundance. A higher education reduced the acrophase (i.e., shifted the distribution to earlier in the year) and a higher BMI and lack of physical activity led to a later acrophase. Generally, increased immune cell count resulted in lower amplitude, and an increased platelet and lymphocyte count was found to increase the acrophase. Importantly, a reduced seasonal amplitude was associated with increased risk for cardiovascular, digestive, genitourinary, and respiratory diseases as well as all-cause mortality. Most of the metabolomic and proteomic markers were associated with mtDNA displacement (i.e., increase of the baseline level) but not acrophase or amplitude. Similarly, we found that there are multiple genetic variants influencing displacement, but none reached genome-wide significance when investigating acrophase or amplitude.

CONCLUSION

Seasonal variation of mtDNA abundance is influenced by environmental, lifestyle and immune parameters. Differences in the seasonal oscillation of mitochondrial abundance could potentially explain discrepancies of previous associations results and might be useful to improve future risk prediction.

Genetic Polymorphisms in Cytochrome P450 Enzymes Involved in Vitamin D Metabolism and the Vitamin D Receptor: Their Clinical Relevance

Individual variations in the active form of vitamin D (Vit.D) arise from a combination of dietary intake, sun exposure, and genetic factors, making it complex and challenging to maintain optimal levels. Among Vit.D-related genes, variations in CYP2R1 and CYP27B1 influence Vit.D synthesis, CYP24A1 regulates its inactivation, and the Vit.D receptor (VDR) mediates Vit.D signaling. These genetic variations contribute to substantial differences in Vit.D concentrations and associated clinical effects. However, there has been a lack of comprehensive, simultaneous exploration of these key genes and their clinical implications. This review provides a systematic analysis of genetic variants in Vit.D-related P450 genes identified in human clinical studies, along with in silico predictions of their functional consequences. Since multiple genes seem to influence the body's response to Vit.D, studying just one genetic variant may not fully explain Vit.D deficiency. A comprehensive evaluation of all Vit.D-related genes could offer valuable insights for advancing personalized medicine in Vit.D management. This study provides a foundation for developing a more personalized approach to Vit.D supplementation and regulation, guided by genetic information.

A multistage double-blind placebo-controlled study to assess the safety and efficacy of transdermal vitamin D phosphate supplementation (TransVitD)

BACKGROUND

Lifestyle changes have meant that it is problematic for many people across the globe to maintain adequate vitamin D concentrations. As UV-catalysed production in the skin, which uses vitamin D-binding protein to facilitate systemic absorption, is the primary source of vitamin D, it is questionable if oral supplementation of this vitamin is the optimal means to replace it. However, supplementing an oil-soluble vitamin via the skin is problematic as it gets stuck in the stratum corneum after topical application. This clinical study will test if a new vitamin D ester, vitamin D phosphate, which is more water-soluble compared to vitamin D, administered via a transdermal patch, can be used to improve vitamin D status.

METHOD

This is a two-part study comprising a dose-escalation with the vitamin D phosphate transdermal patch followed by a randomised, double-blind, placebo-controlled, multiarmed, multistage clinical trial. It is a single-centred, 12-week study that will enrol a maximum of 100 participants. The dose escalation study will monitor safety and tolerability using serum calcium and 25(OH)D3 levels. The blinded, randomised trial will test different dose frequencies for 4 weeks compared to a placebo. Then, after an interim analysis, the best dosing frequency will be assessed against a placebo. The primary outcome for the multistage clinical study will be the percentage change in 25(OH)D3 concentration in the serum (ng/mL) at weeks 4 and 8 compared to baseline. The secondary outcome measures include percentage change in serum vitamin D-binding protein levels, skin interstitial fluid biomarker concentrations, and nail appearance after 4 and 8 weeks compared to baseline.

DISCUSSION

This study will determine if a vitamin D phosphate transdermal patch can improve vitamin D status. In addition, it could provide a better understanding of how vitamin D is absorbed directly into the skin after application by measuring the serum vitamin D-binding protein and skin biomarker responses to transdermal supplementation.

TRIAL REGISTRATION

Clinical Trials.gov NCT06098846, registered on 23rd October 2023.

Effect of Repeated Low-Dose UVR Exposure on Skin Inflammation Threshold, Skin Biomarkers, and Vitamin D in Healthy Adults

UVR can cause photoaging, skin burns, and skin cancer. The skin counters these effects through photoadaptation, which involves melanin production, skin thickening, and immune responses. This study investigated the effects of repeated, suberythemal low-dose UVR on the skin's inflammation threshold, assessed as minimal erythema dose, across different skin phototypes. In addition, epidermal and stratum corneum thickness, melanin index, erythema index, skin and blood levels of immunological biomarkers, and blood vitamin D3 25(OH) were measured. Over 9 weeks, 31 subjects were exposed to UVR (0.8 standard erythema dose) on the lower back 3 times per week. Results showed a 50% increase in minimal erythema dose, with a stronger effect in lighter phototypes. Increase in minimal erythema dose was paralleled by an increase in erythema index. Melanin index and stratum corneum thickness increased significantly by 12 and 34%, respectively, with melanin having a stronger effect on the minimal erythema dose increase. Vitamin D levels rose by 21%, adjusting for seasonal decline. Immunological markers of T helper 1/T helper 2 response and vascular markers declined, indicating local immunosuppression, although no systemic changes in immunological markers were observed. These findings suggest that even low UVR doses are sufficient to induce photoadaptation. Further research is needed to evaluate the long-term benefits and risks of this exposure.

Maternal vitamin D status, fetal growth patterns, and adverse pregnancy outcomes in a multisite prospective pregnancy cohort

BACKGROUND

Few studies have examined maternal vitamin D status and fetal growth patterns across gestation. Furthermore, time points in pregnancy at which maternal vitamin D status is most critical for optimal fetal growth and pregnancy outcomes are uncertain.

OBJECTIVES

Our objective was to examine whether first and second trimester maternal vitamin D status are associated with fetal growth patterns and pregnancy outcomes.

METHODS

We conducted a secondary analysis using data and samples from a multisite prospective cohort study of nulliparous pregnant females in the United States. We measured serum 25-hydroxyvitamin D (25(OH)D) for 351 participants at 6-13 and 16-21 weeks of gestation. Fetal growth was measured by ultrasound at 16-21 and 22-29 weeks of gestation, and neonatal anthropometric measures at birth. We constructed fetal growth curves using length, weight, and head circumference z-scores, and calculated risk of preterm birth (<37 wk) and small for gestational age (SGA). We examined outcomes across 25(OH)D concentrations assessed continuously, using Institute of Medicine (IOM) cutoffs (<50 compared with ≥50 nmol/L), and using exploratory cutoffs (<40, 40-59.9, 60-79.9, ≥80 nmol/L).

RESULTS

Vitamin D insufficiency (25(OH)D <50 nmol/L) was prevalent in 20% of participants in the first trimester. Each 10 nmol/L increase in first trimester 25(OH)D was associated with a 0.05 [95% confidence interval (CI): 0.01, 0.10] increase in length-for-age z-score but was not associated with weight or head circumference. There were no differences in risk of preterm birth or SGA using IOM cutoffs; participants with first trimester 25(OH)D <40 compared with ≥80 nmol/L had 4.35 (95% CI: 1.14, 16.55) times risk of preterm birth. Second trimester 25(OH)D was not associated with fetal growth patterns or with pregnancy outcomes.

CONCLUSIONS

First trimester 25(OH)D is positively associated with linear growth. Low first trimester 25(OH)D (<40 nmol/L) is associated with a higher risk of preterm birth. Second trimester 25(OH)D is not associated with fetal growth or pregnancy outcomes assessed.

Effect of pre-conception serum vitamin D level on pregnancy outcomes in women undergoing in vitro fertilization with fresh embryo transfer: a retrospective analysis

BACKGROUND

This study aims to investigate the association of pre-conception vitamin D levels on adverse pregnancy outcomes in women undergoing in vitro fertilization with fresh embryo transfer.

METHODS

This was a retrospective cohort study using archived serum 25-hydroxyvitamin D measured in the pre-conception period before ovarian stimulation in patients undergoing in vitro fertilization with fresh autologous embryo transfer. A total of 306 women were included and adverse pregnancy outcomes in their resulting pregnancy were recorded. Patients who were vitamin D deficient (< 20ng/ml) were compared with those who were non-deficient (≥20ng/ml) and analysed for any association with adverse pregnancy outcomes.

RESULTS

A total of 16/306 (5.3%) patients had hypertensive disorders of pregnancy (gestational hypertension and/or pre-eclampsia). The adjusted odds ratio for hypertensive disorders of pregnancy using vitamin D deficiency as a reference was 0.190 (95% CI 0.042-0.852) (p = 0.030). Other pregnancy complications were not significantly different with regards to pre-conception vitamin D status.

CONCLUSIONS

Pre-conception vitamin D deficiency is associated with an increased risk of hypertensive disorders in pregnancy in women undergoing in vitro fertilization with fresh embryo transfer.

TRIAL REGISTRATION

HKUCTR 2361 (9th March 2018).

Prevalence and Associated Risk Factors for Hypovitaminosis D in Patients Scheduled for Primary Total Knee Arthroplasty in Germany

OBJECTIVE

Several studies have reported a high prevalence of hypovitaminosis D in orthopedic patients. The purpose of this prospective observational study was to report on the prevalence of hypovitaminosis D in patients scheduled for elective primary total knee arthroplasty (TKA) and its associated risk factors.

METHODS

In this monocentric cohort study, 25(OH) vitamin D serum levels were measured in 687 consecutive patients undergoing primary total knee arthroplasty (TKA) over a period of twelve months. Vitamin D levels were classified into deficiency (<20 ng/mL), insufficiency (20-29 ng/mL), and sufficiency (≥30 ng/mL). The study assessed the association of vitamin D levels with demographic and clinical factors, including age, sex, BMI, smoking status, and season of measurement. Statistical analyses included chi-square tests, correlation analyses, and multiple linear regression to identify significant predictors of vitamin D levels.

RESULTS

The cohort had a mean age of 67.70 ± 8.95 years and a mean BMI of 31.00 ± 5.71 kg/m2. Collectively, 33.9% of patients were vitamin D deficient, a further 32.9% were insufficient, and only 33.2% were sufficient. Vitamin D levels varied significantly with the season and were associated with obesity and smoking. Specifically, there was a small significant inverse correlation between BMI and vitamin D levels (r = -0.17, p < 0.01). Furthermore, regular nicotine abuse was linked to lower vitamin D levels (r = 0.14, p < 0.01). Multiple linear regression analysis reveals that age, BMI, nicotine abuse, and season were small significant predictors of preoperative vitamin D levels (R2 = 0.15, adjusted R2 = 0.12). A total of 121 (17.61%) patients reported routine vitamin D intake prior to surgery. Supplementing patients had a significantly higher mean serum vitamin D level and a significant reduction in the mean length of in-hospital stay (p < 0.01).

CONCLUSIONS

The prevalence of vitamin D insufficiency and deficiency in patients undergoing elective primary TKA is alarmingly high. In ongoing efforts to optimize the efficacy and outcome of the TKA procedure, orthopedic surgeons should be advised to strongly implement the role of perioperative vitamin D levels in their routine practice.

Population Pharmacokinetic Model of Vitamin D3 and Metabolites in Chronic Kidney Disease Patients with Vitamin D Insufficiency and Deficiency

Vitamin D insufficiency and deficiency are highly prevalent in patients with chronic kidney disease (CKD), and their pharmacokinetics are not well described. The primary study objective was to develop a population pharmacokinetic model of oral cholecalciferol (VitD3) and its three major metabolites, 25-hydroxyvitamin D3 (25D3), 1,25-dihydroxyvitamin D3 (1,25D3), and 24,25-dihydroxyvitamin D3 (24,25D3), in CKD patients with vitamin D insufficiency and deficiency. CKD subjects (n = 29) were administered one dose of oral VitD3 (5000 I.U.), and nonlinear mixed effects modeling was used to describe the pharmacokinetics of VitD3 and its metabolites. The simultaneous fit of a two-compartment model for VitD3 and a one-compartment model for each metabolite represented the observed data. A proportional error model explained the residual variability for each compound. No assessed covariate significantly affected the pharmacokinetics of VitD3 and metabolites. Visual predictive plots demonstrated the adequate fit of the pharmacokinetic data of VitD3 and metabolites. This is the first reported population pharmacokinetic modeling of VitD3 and metabolites and has the potential to inform targeted dose individualization strategies for therapy in the CKD population. Based on the simulation, doses of 600 International Unit (I.U.)/day to 1000 I.U./day for 6 months are recommended to obtain the target 25D3 concentration of between 30 and 60 ng/mL. These simulation findings could potentially contribute to the development of personalized dosage regimens for vitamin D treatment in patients with CKD.

Vitamin D status, physical activity and long-term mortality risk after myocardial infarction: a prospective analysis in the Alpha Omega Cohort

AIM

In post-myocardial infarction (MI) patients, we examined independent and combined associations of vitamin D status and physical activity (PA) with long-term mortality, including effect modification by health determinants.

METHODS

We conducted a prospective analysis of 4,837 MI patients from the Alpha Omega Cohort. Baseline blood samples (2002-2006) were assessed for plasma 25-hydroxyvitamin D (25[OH]D) levels using LC-MS/MS. PA was assessed using a validated questionnaire. Patients were followed for mortality through December 2022. HRs for CVD and all-cause mortality were obtained across sex-specific tertiles of 25(OH)D and four categories of PA using Cox models, adjusted for sociodemographic and lifestyle factors. Potential effect modification by health determinants was examined through stratification.

RESULTS

Patients were 69±5.6 years old, 78% was male, 21% had diabetes, and 10% used vitamin D-containing supplements. Over 14.4 years, 3,206 deaths occurred, including 1,244 from CVD. Median 25(OH)D was 21.1 ng/mL and 44% was vitamin D deficient (<20 ng/mL). Higher 25(OH)D levels were associated with lower CVD (HR:0.63, 95%CI:0.54,0.74) and all-cause mortality (HR:0.68, 95%CI:0.62,0.75). For PA levels (high vs. light), HRs were 0.72 (95%CI:0.61,0.85) for CVD mortality and 0.83 (95%CI:0.75,0.92) for all-cause mortality. Patients with low 25(OH)D and no PA had a threefold higher mortality risk than those with high 25(OH)D levels and high PA. The associations were not significantly modified by sex, comorbidities and other health determinants.

CONCLUSIONS

Vitamin D status and PA were inversely and independently associated with long-term risk of CVD and all-cause mortality after MI, regardless of other health determinants.

Vitamin D Status and Cardiovascular Disease in College Athletes After SARS-CoV-2 Infection

OBJECTIVE

To evaluate the association between vitamin D status and CV disease after COVID-19 in college athletes.

DESIGN

Retrospective cohort study.

SETTING

National College Athletic Association Division-I college athletes from a single academic institution.

PATIENTS

A total of 157 athletes (60 female; median age: 20 years) from 9 sports with a positive SARS-CoV-2 test, cardiac magnetic resonance imaging (CMR), and vitamin D level.

INDEPENDENT VARIABLES

Serum 25-hydroxyvitamin D level (primary); age, sex (regression models).

MAIN OUTCOMES MEASURES

Differences in age, sex, race, ethnicity, myocarditis, pericarditis, and CMR metrics by vitamin D status were analyzed. Regression models were used to assess the relationship between vitamin D status and CMR metrics accounting for age and sex.

RESULTS

Low vitamin D (LVD) was found in 33 (21.0%) of athletes, particularly Black males ( P < 0.001). Athletes with LVD had higher biventricular and lower mid-ventricular extracellular volumes, but these differences were not significant when corrected for age and sex. Athletes with LVD had higher left ventricle (LV) mass ( P < 0.001) and LV mass index ( P = 0.001) independent of age and sex. Differences in global circumferential strain were noted but are likely clinically insignificant. Vitamin D status did not associate with myocarditis and pericarditis ( P = 0.544).

CONCLUSIONS

LVD is common in athletes, particularly in Black males. Although athletes with LVD had higher LV mass, cardiac function and tissue characterization did not differ by vitamin D status. Future studies are needed to determine if the differences in LV mass and LV mass index by vitamin D status are clinically significant. This study suggests that vitamin D status does not impact the development of myocarditis or pericarditis after COVID-19 infection.

Correlation of Serum Vitamin D and High-Density Lipoprotein (HDL) Cholesterol Levels With Disease Activity in Rheumatoid Arthritis: A Single-Center Experience From Eastern India

Background Rheumatoid arthritis (RA) is a progressive, symmetric, and erosive polyarthritis with a variety of extraarticular manifestations such as mononeuritis multiplex, central nervous system vasculitis, Felty's syndrome, dyslipidemia, carditis, and interstitial lung disease. Vitamin D plays a role in both adaptive and innate immunity, and its deficiency leads to the development of many autoimmune disorders. Additionally, RA patients have a lipid paradox consisting particularly of dysfunctional and low levels of high-density lipoprotein (HDL) with reduced low-density lipoprotein lowering effect, which increases cardiovascular morbidity and potentiates widespread systemic inflammation. Both are modifiable risk factors. Although there are numerous studies on vitamin D and HDL cholesterol in disease progression in RA, there is sparse literature from India studying both these factors in combination. In this study, we tried to establish the correlation of serum vitamin D and HDL cholesterol levels, if any, with disease activity using the Disease Activity Score 28 Erythrocyte Sedimentation Rate (DAS28 ESR) score. Methods A descriptive cross-sectional study comprising 80 patients was conducted at a tertiary care center in Eastern India over 12 months. Newly diagnosed RA patients aged >17 years satisfying the diagnostic criteria were included. Serum vitamin D level and HDL cholesterol were measured. Then, the DAS28 ESR score was calculated, and a correlation was looked for between serum vitamin D and HDL cholesterol. Results Patients aged 35-43 years accounted for 32 (42.5%) of participants, of whom 58 (72.5%) were females. Almost half, 38 (47.5%), had vitamin D deficiency. The mean vitamin D level was 22.988 ± 10.01 ng/ml. The mean HDL cholesterol level was 42.3 ± 7.23 mg/dl. The mean DAS28-ESR score was 3.81 ± 1.19. A statistically significant inverse correlation was found between vitamin D levels and DAS28 ESR score (p -0.0003) and HDL (p -0.000349). Conclusions Vitamin D deficiency and low HDL cholesterol levels are more common in RA patients. These factors may contribute to increased disease activity. Both are treatable factors in addition to conventional therapies.

Vitamin D and Breast Cancer Risk: Evaluating the Association and Effective Risk Reduction

Introduction

Breast cancer (BC) is the most common cancer among women globally. Vitamin D has been considered a protective factor; however, its relationship with any aspect of the disease remains controversial.

Methods

A cross-sectional, single-center clinical study was conducted between 2015 and 2018, including 141 women diagnosed with BC and 239 women in the control group, with mean ages of 43.1 and 41.7 years, respectively (p = 0.103). Serum levels of vitamin D and lipid profile were measured. Clinical and nutritional data were obtained through interviews and medical records.

Results

The vitamin D dosage presented an average value of 25.5 ng/mL and 31.0 ng/mL in the case and control groups, respectively (p < 0.001). The vitamin D cut-off point for discriminating the presence of BC was 27.45 ng/mL. Additionally, low-density lipoprotein cholesterol levels were higher in the case group (121.4 mg/dL) compared to the control group (110.7 mg/dL) (p = 0.002), whereas high-density lipoprotein cholesterol levels were lower in the case group (47.6 mg/dL) compared to the control group (53.3 mg/dL) (p = 0.001). Alcohol consumption was significantly higher in the case group than in the control group (2.7 vs. 5.3 doses/day; p < 0.001).

Conclusion

The results indicate a significant association between lower vitamin D levels and BC, persisting after multivariate analysis (p < 0.001). These findings could inform prevention strategies, highlighting the importance of maintaining adequate vitamin D levels and potentially identifying a risk group.

The Impact of Vitamin D and L-Cysteine Co-Supplementation on Upregulating Glutathione and Vitamin D-Metabolizing Genes and in the Treatment of Circulating 25-Hydroxy Vitamin D Deficiency

Vitamin D receptors are expressed in many organs and tissues, which suggests that vitamin D (VD) affects physiological functions beyond its role in maintaining bone health. Deficiency or inadequacy of 25(OH)VD is widespread globally. Population studies demonstrate that a positive association exists between a high incidence of VD deficiency and a high incidence of chronic diseases, including dementia, diabetes, and heart disease. However, many subjects have difficulty achieving the required circulating levels of 25(OH)VD even after high-dose VD supplementation, and randomized controlled clinical trials have reported limited therapeutic success post-VD supplementation. Thus, there is a discordance between the benefits of VD supplementation and the prevention of chronic diseases in those with VD deficiency. Why this dissociation exists is currently under debate and is of significant public interest. This review discusses the downregulation of VD-metabolizing genes needed to convert consumed VD into 25(OH)VD to enable its metabolic action exhibited by subjects with metabolic syndrome, obesity, and other chronic diseases. Research findings indicate a positive correlation between the levels of 25(OH)VD and glutathione (GSH) in both healthy and diabetic individuals. Cell culture and animal experiments reveal a novel mechanism through which the status of GSH can positively impact the expression of VD metabolism genes. This review highlights that for better success, VD deficiency needs to be corrected at multiple levels: (i) VD supplements and/or VD-rich foods need to be consumed to provide adequate VD, and (ii) the body needs to be able to upregulate VD-metabolizing genes to convert VD into 25(OH)VD and then to 1,25(OH)2VD to enhance its metabolic action. This review outlines the association between 25(OH)VD deficiency/inadequacy and decreased GSH levels, highlighting the positive impact of combined VD+LC supplementation on upregulating GSH, VD-metabolizing genes, and VDR. These effects have the potential to enhance 25(OH)VD levels and its therapeutic efficacy.

Does behavior mediate the effect of weather on SARS-CoV-2 transmission? evidence from cell-phone data

There is growing evidence that weather alters SARS-CoV-2 transmission, but it remains unclear what drives the phenomenon. One prevailing hypothesis is that people spend more time indoors in cooler weather, leading to increased spread of SARS-CoV-2 related to time spent in confined spaces and close contact with others. However, the evidence in support of that hypothesis is limited and, at times, conflicting. We use a mediation framework, and combine daily weather, COVID-19 hospital surveillance, cellphone-based mobility data and building footprints to estimate the relationship between daily indoor and outdoor weather conditions, mobility, and COVID-19 hospitalizations. We quantify the direct health impacts of weather on COVID-19 hospitalizations and the indirect effects of weather via time spent indoors away-from-home on COVID-19 hospitalizations within five Colorado counties between March 4th 2020 and January 31st 2021. We also evaluated the evidence for seasonal effect modification by comparing the results of all-season (using season as a covariate) to season-stratified models. Four weather conditions were associated with both time spent indoors away-from-home and 12-day lagged COVID-19 hospital admissions in one or more season: high minimum temperature (all-season), low maximum temperature (spring), low minimum absolute humidity (winter), and high solar radiation (all-season & winter). In our mediation analyses, we found evidence that changes in 12-day lagged hospital admissions were primarily via the direct effects of weather conditions, rather than via indirect effects by which weather changes time spent indoors away-from-home. Our findings do not support the hypothesis that weather impacted SARS-CoV-2 transmission via changes in mobility patterns during the first year of the pandemic. Rather, weather appears to have impacted SARS-CoV-2 transmission primarily via mechanisms other than human movement. We recommend further analysis of this phenomenon to determine whether these findings generalize to current SARS-CoV-2 transmission dynamics, as well as other seasonal respiratory pathogens.

Prevalence of the Double Burden of Malnutrition among Adolescents: Associations with Lifestyle Behaviors and Clusters of Social Determinants

The double burden of malnutrition (DBM) is a condition in which malnutrition coexists with overweight, reflecting a new layer of malnutrition. Our objectives were to assess prevalence; test associations between DBM and 24-hour movement behaviors; and investigate whether DBM is associated with clusters of social determinants. Methods: This multicenter cross-sectional study included 1152 adolescents (12 to 17 years old) from four Brazilian cities. Body mass index (BMI, kg/m2) was used to estimate overweight, and the adopted cutoff points took into account the curves established for age and sex: Z-score > 1 and ≤2 (overweight) and Z-score > 2 (obesity). The serum concentration of 25-hydroxyvitamin D [25(OH)D] was stratified into three levels: vitamin D deficiency ≤ 20 ng/mL; vitamin D insufficiency = 21-29 ng/mL; optimal vitamin D ≥ 30 ng/mL. We used multilevel Poisson regression models to estimate prevalence ratios (PRs) and their respective 95% confidence intervals (95%CI) and to analyze the association between DBM and covariates. A significance level of p < 0.05 was considered. Cluster analyses were performed by applying a combination of hierarchical and non-hierarchical methods. Results: A population prevalence of DBM of 7.3% (95% CI: 5.9-8.9) was revealed. A percentage of 19.2% (95% CI: 17.0-21.6) of adolescents were overweight, and 8.3% (95% CI: 6.8-10.1) were obese. A total of 41.5% (95% CI: 38.7-44.4) had vitamin D deficiency, and 25.8% (95% CI: 23.4-28.4) had vitamin D insufficiency. However, 24-hour movement behaviors were not associated with DBM. Adolescents living in the southern region of the country, from public schools whose mothers have higher education, have a 1.94 [PR = 2.94 (95% CI: 1.20-7.23)] times greater chance of developing DBM. These results highlight the importance of specific factors to improve the nutritional health of adolescents, considering the specific social determinants identified in this study.

Longitudinal analysis of vitamin D levels considering sunshine duration and suggestion for a standardised approach for vitamin D supplementation in children and adolescents with obesity

BACKGROUND

Children with obesity have low 25 hydroxy-vitamin D (25-OH-D3) levels compared to lean children. Recommendations on when to start vitamin D supplementation differ largely between countries. Longitudinal data on 25-OH-D3 levels to guide treatment decisions are scarce since they are largely influenced by solar radiation and are difficult to compare.

METHODS

We carried out a retrospective analysis of multiple 25-OH-D3 and parathyroid hormone (PTH) measurements in a cohort of 543 patients without vitamin D supplementation. All measurements were taken at the local paediatric obesity clinic as documented in the German-Austrian-Swiss APV (Prospective Documentation of Overweight Children and Adolescents) registry from 2009 to 2019. Serial 25-OH-D3 and PTH levels were adjusted for sunshine duration over the last 30 days to account for seasonal variation, as well as for sex and body mass index (BMI). We further performed an exploratory analysis of the association of sunshine duration, sex, BMI SDS (standard deviation score), abnormal lipid levels or dysglycemia with the 25-OH-D3 trend.

RESULTS

229 obese patients (mean BMI SDS: 2,58 (± 0,56), 53% females, mean age: 12 (± 3) years, range: 2-21 years) with two, 115 with three and 96 with four repeated 25-OH-D3 measurements were identified. Mean adjusted 25-OH-D3 (48.2 nmol/l) and PTH (34.9 ng/l) levels remained stable over 120 weeks. 5% of the patients had an elevated PTH > 65 ng/l. High total cholesterol ≥ 200 mg/dl and high triglycerides ≥ 130 mg/dl were associated with higher 25-OH-D3 levels.

CONCLUSION

We propose a simple method to include sunshine duration in the analysis of 25-OH-D3 levels to minimise the bias of seasonal variation. Based on our data we established the pragmatic strategy of limiting vitamin D supplementation to patients with biochemical signs of mineralisation disorders such as elevated PTH and alkaline phosphatase (AP). In children with normal PTH and AP we recommend adjustment of calcium intake and increase of outdoor activity instead.

Multiplicative, additive, and interactive associations of 25-hydroxyvitamin D with lung and prostate cancer

Results regarding the epidemiological association of vitamin D with lung (LCA) and prostate cancer (PCA) are controversial. This study tested whether serum 25-hydroxyvitamin D [25(OH)D] concentrations have interactive epidemiological associations with smoking, the number-one risk factor for LCA, and age, the number-one risk factor for PCA. Also, this study investigated whether the associations of 25(OH)D, smoking, age, alcohol consumption, body mass index, diet (the healthy Nordic diet score), and physical activity with incident LCA and PCA are multiplicative or additive. The study of association types makes it easier to select appropriate statistical methods. The Kuopio Ischaemic Heart Disease Risk Factor Study provided the data of 2578 men with 112 LCA and 300 PCA cases over 35 years by the end of 2019. Serum 25(OH)D did not associate with LCA and PCA or interact with smoking and age. The association of smoking with LCA was additive; 13 extra cases per 1000 men every 10 years. Age and alcohol consumption multiplicatively increased the hazard of LCA (hazard ratio, 95% confidence interval for age >50: 3.56, 1.82-6.17; drink per week: 1.01, 1.00-1.03), whereas adherence to healthy Nordic diet decreased it (per score point: 0.95, 0.89-1.00). The association of age >50 with PCA was additive; 2.5 extra cases per 1000 men every 10 years. To conclude, there was no epidemiological relationship of pre-diagnostic 25(OH)D concentrations with the incidence of LCA and PCA. The respective associations of smoking and age >50 with LCA and PCA were additive rather than multiplicative.

Effect of air temperature on serum 25-hydroxyvitamin D concentrations: A single institutional large-scale study in Korea

Vitamin D deficiency is a worldwide health issue especially in women. Serum vitamin D concentrations vary depending on the weather. However, the ideal vitamin D supplementation strategy related to weather remains uncertain. We aimed to investigate the relationship between climate factors and serum 25-hydroxy vitamin D [25(OH)D] concentrations. This study included 11,272 women aged 20-79 who visited a health promotion center for annual checkups between January 2013 and December 2015. We reviewed medical records and collected daily meteorological data. We analyzed the association between serum 25(OH)D concentration and climate factors using simple and multiple regression models and then predicted serum 25(OH)D concentration using multiple fractional polynomial models. The median age of the participants was 51 years (20-79 years), and the mean serum 25(OH)D level was 17.4 ± 8.6 ng/mL. The serum 25(OH)D concentration was lower in young women than in older women. The proportions of women with adequate 25(OH)D levels were 14.9% and 47.0% in the age groups 20-29 and 70-79, respectively. The maximum level of predicted log 25(OH)D was found in September, and the minimum was found in January. In multiple regression analysis, age and monthly mean temperature were associated with 25(OH)D concentrations. Serum 25(OH)D level was predicted using the following formula: log (25(OH)D) = 2.144 + 0.009 × age + 0.018 × ((temperature + 12.4)/10)2 (P < 0.001, adjusted R2 = 0.091). Serum 25(OH)D concentrations changed according to air temperature. An adequate strategy for vitamin D supplementation, based on air temperature, is necessary to maintain healthy serum 25(OH)D levels.

Does behavior mediate the effect of weather on SARS-CoV-2 transmission? Evidence from cell-phone data

Background

There is growing evidence that weather alters SARS-CoV-2 transmission, but it remains unclear what drives the phenomenon. One prevailing hypothesis is that people spend more time indoors in cooler weather, leading to increased spread of SARS-CoV-2 related to time spent in confined spaces and close contact with others. However, the evidence in support of that hypothesis is limited and, at times, conflicting.

Objectives

We aim to evaluate the extent to which weather impacts COVID-19 via time spent away-from-home in indoor spaces, as compared to a direct effect of weather on COVID-19 hospitalization, independent of mobility.

Methods

We use a mediation framework, and combine daily weather, COVID-19 hospital surveillance, cellphone-based mobility data and building footprints to estimate the relationship between daily indoor and outdoor weather conditions, mobility, and COVID-19 hospitalizations. We quantify the direct health impacts of weather on COVID-19 hospitalizations and the indirect effects of weather via time spent indoors away-from-home on COVID-19 hospitalizations within five Colorado counties between March 4th 2020 and January 31st 2021.

Results

We found evidence that changes in 12-day lagged hospital admissions were primarily via the direct effects of weather conditions, rather than via indirect effects by which weather changes time spent indoors away-from-home. Sensitivity analyses evaluating time at home as a mediator were consistent with these conclusions.

Discussion

Our findings do not support the hypothesis that weather impacted SARS-CoV-2 transmission via changes in mobility patterns during the first year of the pandemic. Rather, weather appears to have impacted SARS-CoV-2 transmission primarily via mechanisms other than human movement. We recommend further analysis of this phenomenon to determine whether these findings generalize to current SARS-CoV-2 transmission dynamics and other seasonal respiratory pathogens.

The relationship between the level of vitamin D and ruptured intracranial aneurysms among patients with high sun exposure

Non-traumatic subarachnoid hemorrhage (SAH) accounts for 3-5% of acute strokes. Intracranial aneurysm is the most common cause of non-traumatic SAH. Vitamin D influences the cardiovascular system, including the formation and rupture of cerebral aneurysms. To evaluate the serum vitamin D level in patients living in the tropical zone who suffered aneurysmal subarachnoid hemorrhage and its correlation with demographic and neurological characteristics. This is an analytical cross-sectional study to assess the serum level of vitamin D in a study population of 99 patients treated and diagnosed with aSAH in a public hospital in Recife-PE over a period of 12 months. In the study sample, composed of individuals with high sun exposure due to the lifestyle they lead in a tropical region, we observed hypovitaminosis D (85.9%), with a median of 19.9 ng/ml, although the majority of individuals are skin with high concentration of melanin (Fitzpatrick skin type IV and V). In addition, rates of sun exposure are high to all patients (Solar Index 9.03 P50). Most individuals were female (79.8%); there was no statistical difference in solar exposure/solar index between genders. As for the neurological repercussions, there was no statistical relevance in the clinical prognostic scales evaluated. As the sample was composed mainly of individuals whose economic activity is agriculture, the values of solar index found are vastly higher than those of other studies conducted in high latitude regions. In line with the literature review, some aspects were raised with the objective of justifying such findings that go from the base of the poor diet of these individuals, the increase of melanin in the skin and genetic alterations that directs us to possible mechanisms of natural photoprotection to high sun exposure. Thus, we had a vast majority (85%) of hypovitaminosis D, which in fact makes us wonder if there is any influence of calcitriol on vitamin D receptors in vascular walls and in the cardiovascular system as a whole, which influence bleeding events of this nature. As for the neurological repercussions, measured using assessment scales (Glasgow coma scale, WFNS scale, Hunt-Hess and Fisher's tomographic scale) there was no significant difference in the results. As it is only a descriptive study, the causal relationship of the facts cannot be established. However, in a population exposed to high sun exposure and affected by aneurysmal SAH, there is a significant rate of hypovitaminosis D, which supports the hypothesis that vitamin D plays a role in vascular pathologies, such as cerebral aneurysms and SAH.

Seasonal and Treatment-Related Variation in 25-Hydroxy Vitamin D Concentration in Patients with Rheumatoid Arthritis

Background/Objectives: 25-hydroxy vitamin D (25-OH-D) is a fat-soluble compound that plays many essential functions, including bone formation, neuromuscular functions, and prevention of osteoporosis and inflammation. Recent data indicate that its metabolites are associated with rheumatoid arthritis (RA) progression and neuropathic pain in RA patients. We aimed to assess the effect of RA pharmacotherapy and seasonal variation on serum levels of 25-OH-D in RA patients who received treatment with methotrexate (MTX) or leflunomide (LEF) for at least one year. Methods: This study is a retrospective analysis of data collected from 101 patients with RA who received treatment for at least one year. All of them have supplemented 25-OH-D (2000 IU daily) for at least one year. Results: We observed a significant seasonal variation in 25-OH-D concentration (p = 0.004). Moreover, there were significant differences (p = 0.03) between LEF (50.63 ± 17.73 ng/mL) and MTX (34.73 ± 14.04 ng/mL) treatment groups, but only for the summer population. A correlation was observed between 25-OH-D and RA duration-once again, in the summer population (the whole group-r = -0.64; treatment subgroups-r = -0.82 for LEF and -0.61 for MTX). Deficiency of 25-OH-D (below 20 ng/mL) was confirmed in 28.7% of patients, while 18.8% had suboptimal 25-OH-D levels (20-30 ng/mL). Conclusions: Our results showed that both RA pharmacotherapy and seasonal variation affect the serum levels of 25-OH-D in patients with active RA.

Preterm-Born Young Women Have Weaker Hand Grip Strength Compared to Their Full-Term-Born Peers

Prematurity has been linked to lower muscular fitness and increased morbidity across the human lifespan. Hand grip strength is widely used as a measure of muscle strength. Previous studies have shown inconsistent results regarding the role of vitamin D in hand grip strength. Here, we investigated hand grip strength and the effects of a yearlong vitamin D supplementation in healthy preterm-born young adults. We recruited 38 young adults born preterm at either ≤32 weeks' gestation or <34 weeks' gestation and weighing <1500 g, as well as 39 gender- and age-matched controls, for this study. Anthropometric measurements, hand grip strengths, and vitamin D concentrations were recorded. These investigations were repeated after a yearlong vitamin D supplementation intervention. There was a significant difference in the age- and gender-specific hand grip strength ranks between the preterm- and full-term-born young adults: 57.9% and 30.7%, respectively, were below average (p = 0.009). In the preterm-born group, the females had significantly lower hand grip strengths compared to their full-term-born peers, with a mean difference of -3.46 kg (95% CI: -6.68 to -0.247; p = 0.035). In a linear regression analysis, the preterm-born female adult height was negatively associated with hand grip strength (R2 = 0.24, F (1.43) = 13.61, p < 0.001). The vitamin D concentrations were increased after the supplementation period, with no association with hand grip strength. According to our results, preterm-born young females are at risk for lower muscle strength, independent of their current vitamin D status.

Associations between season, climate, and pediatric alopecia areata flares in Providence, Rhode Island

Patients with alopecia areata (AA) may experience episodic hair loss that follows seasonal patterns. To assess associations between seasonal variation, climate factors, and AA flare frequency in pediatric AA patients, we performed a retrospective chart review of 123 pediatric AA patients at Brown Dermatology (Providence, Rhode Island) who experienced hair loss between January 2017 and December 2019. We assessed association of seasonal variation with monthly occurrence of AA flares. We then assessed association between climate variables and monthly AA hair loss frequency using Spearman rank correlation analyses. We conducted stratified analyses in patients with and without history of atopy. The greatest proportion of hair loss episodes occurred in winter (28.1%), followed by autumn (26.3%), spring (23.8%), and summer (21.7%). We found significant correlations between AA hair loss frequency and air pressure (R = 0.61) and hours of sunlight (R = - 0.60). These correlations remained significant among patients with no history of atopic disease but were not significant among those with history of atopy. Limitations include small sample size. This regional analysis supports the role of climate in AA hair loss episodes through assessment of seasonal occurrences and identification of correlations between climate characteristics and AA flare frequency.

Serum 25-hydroxyvitamin D response to vitamin D supplementation using different lipid delivery systems in middle-aged and older adults: a randomised controlled trial

Food fortification improves vitamin D intakes but is not yet mandated in many countries. Combining vitamin D with different dietary lipids altered vitamin D absorption in in vitro and postprandial studies. This randomised, placebo-controlled trial examined the effect of the lipid composition of a vitamin D-fortified dairy drink on change in 25-hydroxyvitamin D (25(OH)D) concentrations. Sixty-three healthy adults aged 50+ years were randomised to one of the following for 4 weeks: vitamin D-fortified olive oil dairy drink, vitamin D-fortified coconut oil dairy drink, vitamin D supplement or placebo control dairy drink. All vitamin D groups received 20 µg of vitamin D3 daily. Serum was collected at baseline and post-intervention to measure 25(OH)D concentrations and biomarkers of metabolic health. Repeated-measures general linear model ANCOVA (RM GLM ANCOVA) compared changes over time. There was a significant time × treatment interaction effect on 25(OH)D concentrations for those classified as vitamin D-insufficient (P < 0·001) and -sufficient at baseline (P = 0·004). 25(OH)D concentrations increased significantly for all insufficient participants receiving vitamin D3 in any form. However, for vitamin D-sufficient participants at baseline, 25(OH)D concentrations only increased significantly with the coconut oil dairy drink and supplement. There was no effect of vitamin D on biomarkers of metabolic health. Vitamin D fortification of lipid-containing foods may be used in lieu of supplementation when supplement adherence is low or for individuals with dysphagia. These results are important given the recent recommendation to increase vitamin D intakes to 15-20 µg for older adults in Ireland.

Inverse correlation of intact PTH, oxidized PTH as well as non-oxidized PTH with 25-hydroxyvitamin D3 in kidney transplant recipients

Background

25-hydroxyvitamin D (25(OH)D) and potentially also 1,25-dihydroxyvitamin D (1,25(OH)2D) inhibits the synthesis of parathyroid hormone (PTH) in the chief cells of the parathyroid gland. Clinical studies showing a negative correlation between (25(OH)D and PTH are in good agreement with these findings in basic science studies. However, PTH was measured in these studies with the currently clinically used 2nd or 3rd generation intact PTH (iPTH) assay systems. iPTH assays cannot distinguish between oxidized forms of PTH and non-oxidized PTH. Oxidized forms of PTH are the by far most abundant form of PTH in the circulation of patients with impaired kidney function. Oxidation of PTH causes a loss of function of PTH. Given that the clinical studies done so far were performed with an PTH assay systems that mainly detect oxidized forms of PTH, the real relationship between bioactive non-oxidized PTH and 25(OH)D as well as 1,25(OH)2D is still unknown.

Methods

To address this topic, we compared for the first time the relationship between 25(OH)D as well as 1,25(OH)2D and iPTH, oxPTH as well as fully bioactive n-oxPTH in 531 stable kidney transplant recipients in the central clinical laboratories of the Charité. Samples were assessed either directly (iPTH) or after oxPTH (n-oxPTH) was removed using a column that used anti-human oxPTH monoclonal antibodies, a monoclonal rat/mouse parathyroid hormone antibody (MAB) was immobilized onto a column with 500 liters of plasma samples. Spearman correlation analysis and Multivariate linear regression were used to evaluate the correlations between the variables.

Results

There was an inverse correlation between 25(OH)D and all forms of PTH, including oxPTH (iPTH: r=-0.197, p<0.0001; oxPTH: r=-0.203, p<0.0001; n-oxPTH: r=-0.146, p=0.001). No significant correlation was observed between 1,25(OH)2D and all forms of PTH. Multiple linear regression analysis considering age, PTH (iPTH, oxPTH and n-oxPTH), serum calcium, serum phosphor, serum creatinine, fibroblast growth factor 23 (FGF23), osteoprotegerin (OPG), albumin, and sclerostin as confounding factors confirmed these findings. Subgroup analysis showed that our results are not affected by sex and age.

Conclusion

In our study, all forms of PTH are inversely correlated with 25-hydroxyvitamin D (25(OH)D). This finding would be in line with an inhibition of the synthesis of all forms of PTH (bioactive n-oxPTH and oxidized forms of PTH with minor or no bioactivity) in the chief cells of the parathyroid glad.

Fasting plasma glucose and serum 25-hydroxy vitamin D levels in individuals with Middle Eastern and Swedish descent

Purpose

To determine fasting plasma glucose and serum 25-hydroxyvitamin D (s-25(OH)D) levels and associations between abnormal fasting plasma glucose levels and inadequate s-25(OH)D levels in individuals of Middle Eastern and Swedish descent.

Methods

Observational study with individuals without a diabetes diagnosis, 54.5% of Swedish descent and 45.5% of Middle Eastern descent. In total, 830 participants from two primary healthcare centres in Flemingsberg and Jakobsberg, which are southern and northern suburbs, respectively, of Stockholm, Sweden were included in the study.

Results

Prevalence of inadequate s-25(OH)D levels (at or below 50 nmol/L) was 67.2% among those of Middle Eastern descent and 20.5% among those of Swedish descent (P < 0.001). S-25(OH)D levels correlated weakly positively with fasting plasma glucose levels (ρ = 0.20, P = 0.002) in individuals of Middle Eastern descent. Being of Middle Eastern descent (OR 6.7, 95% CI 4.3-10.4) and having abnormal fasting plasma glucose (OR 1.8, 95% CI 1.2-2.9) were independent predictors of having inadequate s-25(OH)D levels.

Conclusions

Healthcare in Sweden should consider testing fasting plasma glucose and s-25(OH)D levels, particularly in individuals of Middle Eastern descent. The unclear relationship between vitamin D and glucose levels warrants investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01226-0.

Vitamin D Status in Diabetic Moroccan Children And Adolescents: a Case-control Study

Background: Type 1 diabetes mellitus (T1DM) incidence is currently increasing worldwide, and different environmental players along with genetic predisposition, could be involved as powerful triggers of this disease onset. In this study, we aim to shed the light on the relationship between 25OHD deficiency and T1DM. Patients and methods: A case-control study was laid out to compare serum 25OHD level between T1DM patients and controls. A total of 147 T1DM patients aged under 19 years old were recruited from our Endocrinology-Diabetology and Nutrition department between October 2014 and December 2019. A total of 147 controls were randomly enlisted from clinical biochemistry laboratory of our center, and were carefully matched. The levels of 25OHD in the serum were determined in T1DM patients and nondiabetic controls. Results: Average serum 25OHD concentration was established in both groups; reaching 19,29 ±6,13 ng/ml in the control arm and 15,02 ± 6,48 ng/ml in the selected group with T1DM independently of the disease duration. However, the mean serum 25OHD concentration was not significantly different between the two T1DM subgroups according to diabetes duration below or above 5 years, and 25OHD concentration remained lower either in winter or summer months. A negative correlation was noticed between HbA1c and serum 25 OHD concentration in T1DM patients and was statistically significant (p<0,05). Conclusion: Key messages on the importance of vitamin D status, particularly in diabetic children and adolescents, should be spread widely in order to start a suitable vitamin supplementation, and establish guidelines regarding its timing at adequate recommended doses..

EMAS position statement: Vitamin D and menopausal health

INTRODUCTION

There is increasing evidence that vitamin D has widespread tissue effects. In addition to osteoporosis, vitamin D deficiency has been associated with cardiovascular disease, diabetes, cancer, infections and neurodegenerative disease. However, the effect of vitamin D supplementation on non-skeletal outcomes requires clarification, especially in postmenopausal women.

AIM

This position statement provides an evidence-based overview of the role of vitamin D in the health of postmenopausal women based on observational and interventional studies.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSIONS

Vitamin D status is determined by measuring serum 25-hydroxyvitamin D levels. Concentrations <20 ng/ml (<50 nmol/l) and <10 ng/ml (<25 nmol/l) are considered to constitute vitamin D deficiency and severe deficiency, respectively. Observational data suggest an association between vitamin D deficiency and adverse health outcomes in postmenopausal women, although they cannot establish causality. The evidence from randomized controlled trials concerning vitamin D supplementation is not robust, since many studies did not consider whether people were deficient at baseline. Moreover, high heterogeneity exists in terms of the population studied, vitamin D dosage, calcium co-administration and duration of intervention. Concerning skeletal health, vitamin D deficiency is associated with low bone mass and an increased risk of fractures. Vitamin D supplementation at maintenance doses of 800-2000 IU/day (20-50 μg/day), after repletion of vitamin D status with higher weekly or daily doses, may be of benefit only when co-administered with calcium (1000-1200 mg/day), especially in the elderly populations and those with severe vitamin D deficiency. Concerning cardiovascular disease, vitamin D deficiency is associated with an increased prevalence of cardiovascular risk factors, mainly metabolic syndrome, type 2 diabetes mellitus and dyslipidemia. Vitamin D deficiency, especially its severe form, is associated with an increased risk of cardiovascular events (coronary heart disease, stroke, mortality), independently of traditional risk factors. Vitamin D supplementation may have a modestly beneficial effect on lipid profile and glucose homeostasis, especially in obese individuals or those ≥60 years old and at doses of ≥2000 IU/day (≥50 μg/day). However, it has no effect on the incidence of cardiovascular events. Concerning cancer, vitamin D deficiency is associated with increased incidence of and mortality from several types of cancer, such as colorectal, lung and breast cancer. However, the data on other types of gynecological cancer are inconsistent. Vitamin D supplementation has no effect on cancer incidence, although a modest reduction in cancer-related mortality has been observed. Concerning infections, vitamin D deficiency has been associated with acute respiratory tract infections, including coronavirus disease 2019 (COVID-19). Vitamin D supplementation may decrease the risk of acute respiratory tract infections and the severity of COVID-19 (not the risk of infection). Concerning menopausal symptomatology, vitamin D deficiency may have a negative impact on some aspects, such as sleep disturbances, depression, sexual function and joint pains. However, vitamin D supplementation has no effect on these, except for vulvovaginal atrophy, at relatively high doses, i.e., 40,000-60,000 IU/week (1000-1500 IU/week) orally or 1000 IU/day (25 μg/day) as a vaginal suppository.

The association between vitamin D deficiency and risk of renal event: Results from the Korean cohort study for outcomes in patients with chronic kidney disease (KNOW-CKD)

Backgrounds

Some observational studies have suggested a possible association between vitamin D deficiency and CKD. However, in most studies, the causality between low levels of vitamin D and risk of renal events could not be explained. We investigated the relationship between vitamin D deficiency and risk of severe CKD stage and renal event in a large-scale prospective cohort study.

Methods

We used data from a prospective cohort of 2,144 patients with available information on serum 25-hydroxyvitamin D (25(OH)D) levels at baseline from KNOW-CKD, 2011-2015 were included. Vitamin D deficiency was defined as serum 25(OH)D levels < 15 ng/mL. We performed a cross-sectional analysis to elucidate the relationship between 25(OH)D and CKD stage using baseline CKD patient data. We further examined a cohort analysis to clarify the association between 25(OH)D and risk of renal event. Renal event was a composite of the first occurrence of a 50% decline in eGFR from the baseline value or the onset of CKD stage 5 (initiation of dialysis or kidney transplantation) across the follow-up period. We also investigated the associations of vitamin D deficiency with risk of renal event according to diabetes and overweight status.

Results

Vitamin D deficiency were significantly associated with an increased risk of severe CKD stage - 1.30-fold (95% CI: 1.10-1.69) for 25(OH)D. Deficiency of 25(OH)D with 1.64-fold (95% CI: 1.32-2.65) was related to renal event compared with the reference. Furthermore, vitamin D deficiency patients with presence of DM and overweight status also displayed higher risk than non-deficient patients for risk of renal event.

Conclusion

Vitamin D deficiency is associated with significantly increased risk of severe CKD stage and renal event.

Vitamin D Metabolites: Analytical Challenges and Clinical Relevance

Recent research activities have provided new insights in vitamin D metabolism in various conditions. Furthermore, substantial progress has been made in the analysis of vitamin D metabolites and related biomarkers, such as vitamin D binding protein. Liquid chromatography tandem mass spectrometric (LC-MS/MS) methods are capable of accurately measuring multiple vitamin D metabolites in parallel. Nevertheless, only 25(OH)D and the biologically active form 1,25(OH)2D are routinely measured in clinical practice. While 25(OH)D remains the analyte of choice for the diagnosis of vitamin D deficiency, 1,25(OH)2D is only recommended in a few conditions with a dysregulated D metabolism. 24,25(OH)2D, free and bioavailable 25(OH)D, and the vitamin D metabolite ratio (VMR) have shown promising results, but technical pitfalls in their quantification, limited clinical data and the lack of reference values, impede their use in clinical practice. LC-MS/MS is the preferred method for the measurement of all vitamin D related analytes as it offers high sensitivity and specificity. In particular, 25(OH)D and 24,25(OH)2D can accurately be measured with this technology. When interpreted together, they seem to provide a functional measure of vitamin D metabolism beyond the analysis of 25(OH)D alone. The determination of VDBP, free and bioavailable 25(OH)D is compromised by unresolved analytical issues, lacking reference intervals and insufficient clinical data. Therefore, future research activities should focus on analytical standardization and exploration of their clinical value. This review provides an overview on established and new vitamin D related biomarkers including their pathophysiological role, preanalytical and analytical aspects, expected values, indications and influencing conditions.

Assessing vitamin D metabolism - four decades of experience

One hundred years ago, the role of vitamin D for bone mineralization and the prevention of rickets was discovered. Vitamin D comprises a group of over 50 metabolites with multiple functions that go far beyond calcium homeostasis and bone mineralization. Approximately 50 years ago, first methods for the measurement of 25-hydroxyvitamin D (25(OH)D) in human blood were developed. Over the years, different analytical principals were employed including competitive protein binding assays, high-performance liquid chromatography, various immunoassay and mass spectrometric formats. Until the recent standardization of serum 25(OH)D measurement, agreement between methods was unsatisfactory. Since then, comparability has improved, but substantial variability between methods remains. With the advent of liquid chromatography tandem mass spectrometry (LC-MS/MS), the accurate determination of 25(OH)D and other metabolites, such as 24,25(OH)2D, becomes increasingly accessible for clinical laboratories. Easy access to 25(OH)D testing has triggered extensive clinical research showing that large parts of the population are vitamin D deficient. The variable response of vitamin D deficient individuals to supplementation indicates that assessing patients' vitamin D stores by measuring 25(OH)D provides limited insight into the metabolic situation. Meanwhile, first evidence has emerged suggesting that the simultaneous measurement of 25(OH)D, 24,25(OH)2D and other metabolites allows a dynamic evaluation of patients' vitamin D status on metabolic principals. This may help to identify patients with functional vitamin D deficiency from those without. It can be expected that research into the assessment vitamin D status will continue for another 50 years and that this will help rationalizing our approach in clinical practice.

Lack of significant seasonal association between serum 25(OH)D concentration, muscle mass and strength in postmenopausal women from the D-FINES longitudinal study

The aim of the present study was to assess the seasonal relationship between serum 25(OH)D concentration, lean mass and muscle strength. This was a secondary data analysis of a subgroup of 102 postmenopausal women participating in the 2006-2007 D-FINES (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) study. The cohort was assessed as two age subgroups: <65 years (n=80) and ≥65 years (n=22). Outcome measures included lean mass (DXA), muscle strength (handgrip dynamometry) and serum 25(OH)D concentration (enzymeimmunoassay). Derived outcomes included appendicular skeletal muscle mass (ASM) and relative appendicular skeletal muscle index (RASM). Sarcopenia status was assessed using the European Working Group on Sarcopenia in Older People 2018 criteria. Non-parametric partial correlation using BMI as a covariate was used to evaluate the study aims. There were no statistically significant associations between total lean mass, ASM or RASM and 25(OH)D in any group at any season. There was a trend for handgrip strength to be positively associated with serum 25(OH)D concentration. There was a trend showing a higher prevalence of sarcopenia in women ≥65 years. Sarcopenia status appeared transient for five women. In conclusion, the present study found no significant association between vitamin D status and functional indicators of musculoskeletal health, which were additionally not affected by season.

Comprehensive Analysis of Seasonal and Geographical Variation in UVB Radiation Relevant for Vitamin D Production in Europe

Dermal synthesis, following sun exposure, is the main source of vitamin D. This study characterizes ambient UVB radiation relevant for vitamin D production in Europe. A biological weighing function was applied to data from the Tropospheric Emissions Monitoring Internet Service (TEMIS) for 46 capital cities over an 18-year period (2004-2021) to isolate wavelengths relevant for vitamin D production (D-UVB). Cumulative and weighted D-UVB (CW-D-UVB) were calculated to approximate seasonal vitamin D accumulation and diminution. Monthly 25(OH)D concentration measurements were extracted from published reports. All data were analyzed by location and time. Despite a moderate latitudinal range (35-64° N), we observed large-up to five-fold-regional differences: the highest mean diurnal D-UVB dose of 5.57 kJ/m2 (SD = 3.55 kJ/m2) was observed in Nicosia (Cyprus) and the lowest in Reykjavik (Iceland, 1.16 ± 1.29 kJ/m2). Seasonal differences in diurnal D-UVB dose were even more pronounced, with a median 36-fold difference between annual peak and trough depending on a location (range: 10- to 525-fold). The mean duration of "vitamin D winter" was 126 days but varied widely (4 to 215 days). Monthly CW-D-UVB and 25(OH)D changes were very strongly correlated: the changes in 25(OH)D concentration increased by 12.6 nmol/L for every 100 kJ/m2 increment of CW-D-UVB in population-based studies (r2 = 0.79, p-value = 1.16 × 10-37). Understanding the differences in D-UVB radiation can help understand determinants of vitamin D status and guide region- and season-specific safe and effective sunlight exposure recommendations and vitamin D supplementation guidelines.

Changes in Vitamin D Status in Korean Adults during the COVID-19 Pandemic

The aim of this study was to investigate changes in 25(OH)D (25-hydroxyvitamin D) levels and in the vitamin D status of Korean adults before and during the coronavirus disease (COVID-19) pandemic. This study compared serum 25(OH)D levels before and after the pandemic in 1483 adults aged 19 years and older who were screened at a university hospital. Subjects were selected only from participants tested in the same season before and after the pandemic. The pre-COVID-19 testing period was from 1 March 2018 to 31 November 2019; the testing period in the COVID-19 era was from 1 June 2020 to 31 November 2021. The mean 25(OH)D level for all participants was 21.4 ± 10.2 ng/mL prior to the outbreak of COVID-19, which increased to 23.6 ± 11.8 ng/mL during the COVID-19 lockdown period (p < 0.001). The increase was particularly dramatic in elderly females (28.8 ± 12.3 ng/mL to 37.7 ± 18.6 ng/mL, p = 0.008). The prevalence of vitamin D deficiency decreased in both males (48.4% to 44.5%, p = 0.005) and females (57.0% to 46.0%, p < 0.001). In conclusion, 25(OH)D levels in Korean adults increased during the COVID-19 era, and the prevalence of vitamin D deficiency decreased accordingly.

IMPACT OF GRAVES' DISEASE AND ANTITHYROID DRUG THERAPY ON BONE MINERAL DENSITY - PATHOPHYSIOLOGICAL MECHANISMS AND CLINICAL RELEVANCE

Graves' disease is an autoimmune disease characterized by excessive thyroid hormone production. One of the consequences of that state can be a decrease in bone mineral density (BMD). Graves' disease is often treated with antithyroid drugs (ATD) as first line therapy, which can lead to disease remission. Moreover, recent data show that improvement in BMD can be expected. However, vitamin D deficiency can coexist along with Graves' disease, which is also involved in the process of bone remodeling. It is still not known whether lower values of vitamin D can contribute to onset of Graves' disease and if its supplementation might be helpful in therapy for hyperthyroidism. In the past couple of decades, osteopenia and osteoporosis have become a major health burden not only in post-menopausal women but also as a result of other diseases, leading to extensive research into various pathophysiological mechanisms responsible for bone remodeling. The Wnt (wingless integrated) signaling pathway is a very important factor in bone homeostasis, especially the canonical pathway. Present data indicate that stimulation of the Wnt pathway leads to bone mass increase and, in contrast, its inhibition leads to bone mass decrease. Hence, inhibitors of the canonical Wnt pathway became the focus of interest, in particular sclerostin and dickkopf 1 (DKK1). Hyperthyroidism and osteopenia/osteoporosis are quite common today and can coexist together or as separate entities. In this article, we aimed to give an overview of possible associations and potential mutual pathophysiological mechanisms.

Retinol Binding Protein, Sunlight Hours, and the Influenza Virus-Specific Immune Response

Healthy pediatric immune responses depend on adequate vitamin A and D levels. Relationships between solar ultraviolet B (UVB) radiation and vitamin D are well understood, while relationships between sunlight, vitamin A, and its serum escort, retinol binding protein (RBP), are not. A pediatric clinical study enrolled 2–8-year-old children at various times between September 2016 and March 2017, inclusive, in Memphis, Tennessee. A serum sample from each child was then assayed to examine the influence of season on vitamin levels. We found that RBP and RBP/retinol molar ratios decreased in winter months and RBP/retinol ratios correlated positively with the average daily sunlight hours per month. A food frequency questionnaire given to parents/guardians indicated a shift in dietary intake from plant-based foods to animal-based foods by children between winter and spring months. This translated to higher retinol and zinc (integral to RBP–transthyretin–retinol complexes) in the spring, perhaps explaining the seasonal influence on RBP/retinol. RBP and retinol were associated positively with IgG/IgM and IgA/IgM ratios. RBP and retinol, but not 25(OH)D, also correlated positively with influenza virus-specific antibodies. Retinol correlated negatively, while 25(OH)D correlated positively, with certain serum cytokine/chemokine levels. Significant differences in 25(OH)D, immunoglobulin ratios, and cytokines/chemokines were observed between black and white children. In sum, seasonal changes in dietary foods rich in retinol and zinc may have influenced RBP levels, which in turn influenced innate and adaptive immune responses. Results encourage routine monitoring and reporting of season, RBP, and vitamin levels in future clinical studies, as seasons may affect sunlight exposures, diet, vitamin levels, and immune protection against infectious disease.

Seasonality of Hashimoto Thyroiditis: Infodemiology Study of Google Trends Data

BACKGROUND

Hashimoto thyroiditis (HT) is an autoimmune thyroid disease and the leading cause of hypothyroidism in areas with sufficient iodine intake. The quality-of-life impact and financial burden of hypothyroidism and HT highlight the need for additional research investigating the disease etiology with the aim of revealing potential modifiable risk factors.

OBJECTIVE

Implementation of measures against such risk factors, once identified, has the potential to lessen the financial burden while also improving the quality of life of many individuals. Therefore, we aimed to examine the potential seasonality of HT in Europe using the Google Trends data to explore whether there is a seasonal characteristic of Google searches regarding HT, examine the potential impact of the countries' geographic location on the potential seasonality, and identify potential modifiable risk factors for HT, thereby inspiring future research on the topic.

METHODS

Monthly Google Trends data on the search topic "Hashimoto thyroiditis" were retrieved in a 17-year time frame from January 2004 to December 2020 for 36 European countries. A cosinor model analysis was conducted to evaluate potential seasonality. Simple linear regression was used to estimate the potential effect of latitude and longitude on seasonal amplitude and phase of the model outputs.

RESULTS

Of 36 included European countries, significant seasonality was observed in 30 (83%) countries. Most phase peaks occurred in spring (14/30, 46.7%) and winter (8/30, 26.7%). A statistically significant effect was observed regarding the effect of geographical latitude on cosinor model amplitude (y = -3.23 + 0.13 x; R2=0.29; P=.002). Seasonal increases in HT search volume may therefore be a consequence of an increased incidence or higher disease activity. It is particularly interesting that in most countries, a seasonal peak occurred in spring and winter months; when viewed in the context of the statistically significant impact of geographical latitude on seasonality amplitude, this may indicate the potential role of vitamin D levels in the seasonality of HT.

CONCLUSIONS

Significant seasonality of HT Google Trends search volume was observed in our study, with seasonal peaks in most countries occurring in spring and winter and with a significant impact of latitude on seasonality amplitude. Further studies on the topic of seasonality in HT and factors impacting it are required.

Nutritional Deficiencies 3 Years After Sleeve Gastrectomy Can Be Limited by a Specialized Multivitamin Supplement

Purpose

Lifelong daily multivitamin supplementation is highly recommended after sleeve gastrectomy (SG). Based on previous research, a specialized multivitamin supplement (MVS) for SG patients was developed and optimized (WLS Optimum 1.0 and 2.0). This study presents its mid-term effectives and compares micronutrient status of SG patients using this specialized MVS to users of standard MVS (sMVS) and non-users of multivitamin supplementation during the first three years post-surgery.

Materials and Methods

Of the 226 participants that were included at baseline, yearly follow-up blood tests were completed by 193 participants (85%) at 12 months, 176 participants (78%) at 24 months, and 140 participants (62%) at 36 months of follow-up. At each time point, participants were divided into four groups: (1) Optimum 1.0, (2) Optimum 2.0, (3) sMVS, and (4) non-users. Serum concentrations (linear mixed-effects models) and the prevalence of micronutrient deficiencies (chi-square tests) during follow-up were compared between the groups.

Results

Users of specialized MVS (Optimum 1.0 and 2.0) had higher serum concentrations of hemoglobin, folic acid, and vitamin D compared to sMVS users and non-users during follow-up. Serum concentrations of vitamin B12 and (corrected) calcium were also higher in specialized MVS users than in non-users. Overall, fewer deficiencies for folic acid and vitamin D were observed in the Optimum groups.

Conclusion

Although the perfect multivitamin supplement for all SG patients does not exist, WLS Optimum was more effective in sustaining normal serum concentrations than standard, over-the-counter supplementation. Non-users of MVS presented with most micronutrient deficiencies and will evidently develop poor nutritional status on the longer term.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-022-06256-w.

Valuing the Diversity of Research Methods to Advance Nutrition Science

The ASN Board of Directors appointed the Nutrition Research Task Force to develop a report on scientific methods used in nutrition science to advance discovery, interpretation, and application of knowledge in the field. The genesis of this report was growing concern about the tone of discourse among nutrition professionals and the implications of acrimony on the productive study and translation of nutrition science. Too often, honest differences of opinion are cast as conflicts instead of areas of needed collaboration. Recognition of the value (and limitations) of contributions from well-executed nutrition science derived from the various approaches used in the discipline, as well as appreciation of how their layering will yield the strongest evidence base, will provide a basis for greater productivity and impact. Greater collaborative efforts within the field of nutrition science will require an understanding that each method or approach has a place and function that should be valued and used together to create the nutrition evidence base. Precision nutrition was identified as an important emerging nutrition topic by the preponderance of task force members, and this theme was adopted for the report because it lent itself to integration of many approaches in nutrition science. Although the primary audience for this report is nutrition researchers and other nutrition professionals, a secondary aim is to develop a document useful for the various audiences that translate nutrition research, including journalists, clinicians, and policymakers. The intent is to promote accurate, transparent, verifiable evidence-based communication about nutrition science. This will facilitate reasoned interpretation and application of emerging findings and, thereby, improve understanding and trust in nutrition science and appropriate characterization, development, and adoption of recommendations.

Temporal Association of Reduced Serum Vitamin D with COVID-19 Infection: Two Single-Institution Case–Control Studies

(1) Background: Vitamin D supplementation has been proposed for the prevention and treatment of COVID-19, but it is not clear if reduced serum vitamin D predisposes individuals to COVID-19 and/or is a secondary consequence of infection. This study assessed the temporal association between serum vitamin D and COVID-19 with two single-institution case–control studies through the University of California San Diego (UCSD) Health System. (2) Methods: This study included patients who tested positive for COVID-19 from 1 January to 30 September 2020 with serum 25-hydroxy-vitamin D (25(OH)D) measured within 180 days of diagnosis. Patients were separated based on whether 25(OH)D was measured before (n = 107 cases, 214 controls) or after (n = 203 cases, 406 controls) COVID-19 diagnosis. COVID-19 infection status was the outcome variable in the pre-diagnosis study, whereas serum 25(OH)D level was the outcome variable in the post-diagnosis study. (3) Results: Serum 25(OH)D levels were not associated with the odds of subsequent COVID-19 infection (OR 1.0, 95% CI: 1.0 to 1.0, p = 0.98). However, COVID-19-positive individuals had serum 25(OH)D measurements that were 2.7 ng/mL lower than the controls (95% CI: −5.2 to −0.2, p = 0.03). (4) Conclusions: In our study population, serum 25(OH)D levels were not associated with the risk of acquiring COVID-19 infection but were reduced in subjects after COVID-19 infection. These results support the possibility that reduced serum 25(OH)D is a consequence and not a cause of COVID-19 infection.

Analyzing the relationship between the vitamin D deficiency and COVID-19 mortality rate and modeling the time-delay interactions between body's immune healthy cells, infected cells, and virus particles with the effect of vitamin D levels

This paper presents some recent views on the aspects of vitamin D levels in relation to the COVID-19 infections and analyzes the relationship between the prevalence rates of vitamin D deficiency and COVID-19 death rates per million of various countries in Europe and Asia using the data from the PubMed database. The paper also discusses a new mathematical model of time-delay interactions between the body's immune healthy cells, infected cells, and virus particles with the effect of vitamin D levels. The model can be used to monitor the timely progression of healthy immune cells with the effects of the levels of vitamin D and probiotics supplement. It also can help to predict when the infected cells and virus particles free state can ever be reached as time progresses. The consideration of the time delay in the modeling due to effects of the infected cells or virus particles and the growth of healthy cells is also an important factor that can significantly change the outcomes of the body's immune cells as well as the infections.

ESPEN micronutrient guideline

BACKGROUND

Trace elements and vitamins, named together micronutrients (MNs), are essential for human metabolism. Recent research has shown the importance of MNs in common pathologies, with significant deficiencies impacting the outcome.

OBJECTIVE

This guideline aims to provide information for daily clinical nutrition practice regarding assessment of MN status, monitoring, and prescription. It proposes a consensus terminology, since many words are used imprecisely, resulting in confusion. This is particularly true for the words "deficiency", "repletion", "complement", and "supplement".

METHODS

The expert group attempted to apply the 2015 standard operating procedures (SOP) for ESPEN which focuses on disease. However, this approach could not be applied due to the multiple diseases requiring clinical nutrition resulting in one text for each MN, rather than for diseases. An extensive search of the literature was conducted in the databases Medline, PubMed, Cochrane, Google Scholar, and CINAHL. The search focused on physiological data, historical evidence (published before PubMed release in 1996), and observational and/or randomized trials. For each MN, the main functions, optimal analytical methods, impact of inflammation, potential toxicity, and provision during enteral or parenteral nutrition were addressed. The SOP wording was applied for strength of recommendations.

RESULTS

There was a limited number of interventional trials, preventing meta-analysis and leading to a low level of evidence. The recommendations underwent a consensus process, which resulted in a percentage of agreement (%): strong consensus required of >90% of votes. Altogether the guideline proposes sets of recommendations for 26 MNs, resulting in 170 single recommendations. Critical MNs were identified with deficiencies being present in numerous acute and chronic diseases. Monitoring and management strategies are proposed.

CONCLUSION

This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.

Analysis of the Seasonal Fluctuation of γδ T Cells and Its Potential Relation with Vitamin D3

In addition to its role in bone metabolism, vitamin D3 exerts immunomodulatory effects and has been proposed to contribute to seasonal variation of immune cells. This might be linked to higher vitamin D3 levels in summer than in winter due to differential sun exposure. γδ T cells comprise a numerically small subset of T cells in the blood, which contribute to anti-infective and antitumor immunity. We studied the seasonal fluctuation of γδ T cells, the possible influence of vitamin D3, and the effect of the active metabolite 1α,25(OH)2D3 on the in vitro activation of human γδ T cells. In a retrospective analysis with 2625 samples of random blood donors, we observed higher proportions of γδ T cells in winter when compared with summer. In a prospective study over one year with a small cohort of healthy adults who did or did not take oral vitamin D3 supplementation, higher proportions of γδ T cells were present in donors without oral vitamin D3 uptake, particularly in spring. However, γδ T cell frequency in blood did not directly correlate with serum levels of 25(OH)D3. The active metabolite 1α,25(OH)2D3 inhibited the in vitro activation of γδ T cells at the level of proliferation, cytotoxicity, and interferon-γ production. Our study reveals novel insights into the seasonal fluctuation of γδ T cells and the immunomodulatory effects of vitamin D3.

The Prevalence of Vitamin D Deficiency in Patients Undergoing Total Knee Arthroplasty: A Propensity Score Matching Analysis

PURPOSE

We investigated and compared the serum 25-OH vitamin D [25(OH)D] level and prevalence of vitamin D deficiency (VDD) between patients who underwent total knee arthroplasty (TKA) and healthy participants through a matched analysis.

METHODS

The unmatched case group consisted of 824 patients who underwent TKA and the unmatched control group 2,794 healthy participants examined at our institution. The control group was matched on the various characteristics-sex, age, weight, body mass index (BMI), blood chemistry, and season of sampling-through propensity score matching (PSM). After PSM, 501 and 721 patients were matched in the case and control group, respectively. Levels of blood chemistry including 25(OH)D were examined and VDD was defined as < 20 ng/mL.

RESULTS

The average serum 25(OH)D level was significantly lower in the OA group (15.3 ng/mL) than that in the control group (19.9 ng/mL, p < 0.001). When categorized using a 20 ng/mL cutoff, the VDD prevalence was 75.0% in the OA group and 59.4% in the control group. The prevalence of vitamin D insufficiency was 18.4% in the OA group and 24.5% in the control group. The prevalence of vitamin D sufficiency was 6.8% in the OA group and 15.9% in the control group (p < 0.001).

CONCLUSIONS

The patients who underwent TKA had lower serum 25(OH)D level and higher VDD prevalence compared to the healthy participants who matched using PSM. There were no differences in VDD rates by sex or obesity and the VDD prevalence was more than 70% during all season. Therefore, in patients undergoing TKA, general attention to VDD is required regardless of sex, obesity, and season. Serum 25-OH vitamin D [25(OH)D] level and vitamin D deficiency (VDD) prevalence were compared between patients undergoing total knee arthroplasty and healthy individuals. The differences in serum 25(OH)D level and VDD prevalence were significant between the two groups after propensity score matching.

Seasonal variation in calcium treatment after thyroidectomy as surrogate for post-operative hypocalcemia: a retrospective register-based national cohort study

Background

Hypocalcemia is one of the most common complications of thyroidectomy, and vitamin D deficiency has been found to be an independent risk factor. Sweden is located north of the 55th latitude, resulting in a significant seasonal variation in sun exposure, thereby large variation in the naturally occurring levels of vitamin D. This study aimed to determine if there is a correlation between season of surgery and post-thyroidectomy hypocalcemia.

Methods

We conducted a retrospective register-based observation study on patients who had undergone total thyroidectomy during 2008–2015. In total, 7125 patients operated in Swedish facilities were identified via the Scandinavian Quality Register for Thyroid, Parathyroid, and Adrenal Surgery (SQRTPA). Patients operated during February–April were included in the dark group and patients operated during August–October were included in the bright group. Further stratification was made on the indication for surgery. The primary outcome was post-operative calcium treatment due to hypocalcemia, defined as having received calcium orally or intravenously before discharge.

Results

The risk of receiving post-operative calcium treatment was significantly lower in the bright group (29.7%) compared to the dark group (35.1%), with a relative risk of 0.846 (P < 0.001). This correlation held true if the indication for surgery was goiter or thyrotoxicosis. For malignancy, there was no significant difference between the groups.

Conclusion

In this cohort, total thyroidectomy performed during August–October was associated with a lower rate of calcium treatment given post-operatively when compared to total thyroidectomy performed during February–April. This would indicate a decreased risk of post-operative hypocalcemia if surgery was carried out after the brighter season.

How competing risks affect the epidemiological relationship between vitamin D and prostate cancer incidence? A population-based study

We hypothesized that controversial results regarding the epidemiological relationship between circulating 25-hydroxyvitamin D, 25(OH)D, and risk of prostate cancer (PCA) incidence are partly due to competing risks. To test the hypothesis, we studied associations across 25(OH)D, PCA and death in 2578 middle-aged men belonging to the Kuopio Ischaemic Heart Disease Risk Factor Study. The men were free of cancer at baseline, and the mean (SD) follow-up time was 23.3 (9.1) years. During this period, 296 men had a PCA diagnosis, and 1448 men died without the PCA diagnosis. The absolute risk of developing PCA was highest in the highest 25(OH)D tertile (15%), whereas that of death was highest in the lowest 25(OH)D tertile (67%). A competing risk analysis showed that belonging to the highest 25(OH)D tertile increased the risk of PCA incidence and improved survival with the respective hazard ratios (HR) of 1.35 (95% CI = 1.07-1.70) and 0.79 (95% CI = 0.71-0.89). Adjusting for 10 covariates together with 25(OH)D did not significantly change the results, but the respective adjusted HRs for PCA and death were 1.20 and 0.87. To conclude, the competing risk analysis did not eliminate the direct relationship between 25(OH)D and PCA but rather strengthened it.

Leukocyte telomere length as a compensatory mechanism in vitamin D metabolism

Vitamin D deficiency is common among postmenopausal women. Telomere length can be a potential protective mechanism for age-related diseases. The objective of our study is to examine the association of vitamin D supplementation on leukocyte telomere length (LTL) in healthy postmenopausal women with vitamin D deficiency. The study was designed as a placebo-controlled study to investigate the short-term effects of vitamin D supplementation and seasonal changes on vitamin D related parameters, including 25(OH)D, 1,25(OH)2D parathormone (PTH), Vitamin D binding protein (VDBP), vitamin D receptor (VDR), and telomere length in a cohort of postmenopausal women (n = 102). The group was divided as supplementation (n = 52) and placebo groups (n = 50). All parameters were measured before and after treatment. Serum VDBP levels were measured by ELISA method and VDR, GC (VDBP) gene expressions and relative telomere lengths were measured in peripheral blood mononuclear cells (PBMC) using a quantitative real-time PCR method. The results demonstrate that baseline levels were similar between the groups. After vitamin D supplementation 25(OH)D, 1,25(OH)2D, PTH and VDBP levels were changed significantly compared to the placebo group. At the end of the study period, LTL levels were significantly increased in both groups and this change was more prominent in placebo group. The change in GC expression was significant between treatment and placebo groups but VDR expression remained unchanged. Even though the study was designed to solely assess the effects of vitamin D supplementation, LTL was significantly increased in the whole study group in summer months suggesting that LTL levels are affected by sun exposure and seasonal changes rather than supplementation. The study displayed the short-term effect of Vitamin D supplementation on vitamin D, PTH levels, LTL and vitamin D associated gene expressions. The relation between Vitamin D and LTL is not linear and could be confounded by several factors such as the population differences, regional and seasonal changes in sun exposure.

25-Hydroxyvitamin D in Cancer Patients Admitted to Palliative Care: A Post-Hoc Analysis of the Swedish Trial 'Palliative-D'

The purpose of this study is to explore 25-hydroxyvitamin D (25-OHD) levels in patients with cancer in the palliative phase in relation to season, sex, age, tumor type, colectomy, and survival. To this end, we performed a post-hoc analysis of ‘Palliative-D’, a randomized placebo-controlled, double-blind trial investigating the effect of daily supplementation with 4000 IU of vitamin D for 12 weeks on pain in patients in palliative cancer care. In the screening cohort (n = 530), 10% of patients had 25-OHD levels < 25 nmol/L, 50% < 50, and 84% < 75 nmol/L. Baseline 25-OHD did not differ between seasons or tumor type and was not correlated with survival time. In vitamin D deficient patients supplemented with vitamin D (n = 67), 86% reached sufficient levels, i.e., >50 nmol/L, after 12 weeks. An increase in 25-OHD was larger in supplemented women than in men (53 vs. 37 nmol/L, p = 0.02) and was not affected by season. In the placebo-group (n = 83), decreased levels of 25-OHD levels were noted during the study period for patients recruited during the last quarter of the year. In conclusion, cancer patients in palliative phase have adequate increase in 25-OHD after vitamin D supplementation regardless of season, age, tumor type, or colectomy.

Differences in Fat-Free Mass According to Serum Vitamin D Level and Calcium Intake: Korea National Health and Nutrition Examination Survey 2008-2011

We analyzed the differences in fat-free mass (FFM) according to serum vitamin D level (VitD) and daily calcium intake (Ca) in 14,444 adults aged over 19 years. We used data from the 4th and 5th Korea National Health and Nutrition Examination Surveys (2008–2011). FFM was measured using dual-energy X-ray absorptiometry. VitD was classified as insufficient or sufficient (cutoff: 20 ng/mL). Ca was classified as unsatisfactory or satisfactory (recommended daily intake: 700 mg). In men, the FFM of group 2 (VitD ≥ 20 ng/mL; Ca < 700 mg), group 3 (VitD < 20 ng/mL; Ca ≥ 700 mg) and group 4 (VitD ≥ 20 ng/mL; Ca ≥ 700 mg) was 0.50 kg (95% confidence interval (CI), 0.084–0.92), 0.78 kg (95% CI, 0.26–1.29) and 1.58 kg (95% CI, 0.95–2.21) higher than that of group 1 (VitD < 20 ng/mL; Ca < 700 mg), respectively. In women, a 1 ng/mL increase in VitD was associated with a 0.023 kg increase in FFM (95% CI, 0.003–0.043) and a 1 g increase in Ca was associated with a 0.62 kg increase in FFM (95% CI, 0.067–1.16). High VitD and Ca were associated with a high FFM.