Vitamin D: a growing perspective

Age-related changes in vitamin D metabolism and vitamin D receptor expression in equine alveolar macrophages: a preliminary study

The vitamin D receptor (VDR)-vitamin D axis modulates pulmonary immunity in people but its role in equine immunity is unknown. Bacterial pneumonia causes high morbidity/mortality in foals and alveolar macrophages (AMφ) are important for pulmonary defenses. Age-related variations in vitamin D-mediated function of AMφ might contribute to the foal's susceptibility to pneumonia. Our aim was to assess the impact of age on equine vitamin D metabolism and VDR expression in AMφ. AMφ and plasma was collected from healthy foals (2, 4 and 8 weeks old) and adult horses (once). AMφ VDR expression was determined via RT-qPCR and plasma vitamin D metabolites quantified via immunoassays. Data were analyzed with linear mixed models. Inactive-vitamin D metabolite concentrations were lowest in foals at 2 weeks and lower at 2 and 4 weeks compared to adults (P < 0.001). Active-vitamin D metabolite concentrations were higher in foals than adults (P < 0.05). VDR expression was detected in AMφ in all animals and was highest in 2-week-old foals. Vitamin D metabolism and AMφ VDR expression are impacted by age in horses. This may have immunological consequences in foals given the key role that the VDR-vitamin D axis has in pulmonary immunity in other species.

Exposure to famine in every stage of life and the risk of osteoporosis and fractures later in life: A cross-sectional study

BACKGROUND AND OBJECTIVE

Data on the association between early-life famine exposure and osteoporosis and fractures remain limited and inconclusive. The aim of this study was to investigate the correlation between famine exposure and osteoporosis and fractures.

METHODS

We performed a cross-sectional analysis using the first follow-up survey data from the China Cardiometabolic Disease and Cancer Cohort Study from 2014 to 2016. We classified 4807 Lanzhou participants into seven groups based on their birthday (non-exposed or exposed in the fetal stage, early childhood, mid-childhood, late childhood, adolescence, or early adulthood). And we combined the non-exposed and early-adulthood exposed groups as a control group, which was called "age balanced group". This age-balanced group was used as the control group to further evaluate the risk of osteoporosis and fracture. We used multiple logistic regression to estimate the association between famine exposure and the risk of osteoporosis (T-score ≤ -1.8 by QUS) and self-reported fracture.

RESULTS

In women, compared to the age-balanced group, the odds ratios (95 % CI) for the risk of osteoporosis were 1.400(1.034, 1.897), 1.630(1.268, 2.095), 1.707(1.314, 2.218), 2.150(1.732.2.668) and 2.885(2.286,3.641) in the fetal stage, early childhood, mid-childhood, late childhood and adolescence famine-exposed cohorts. In men, no association between famine and osteoporosis was noted with exposed cohort compared with the age-balanced control cohort (p > 0.05). Interestingly, the association between famine exposure and fractures was slightly different from the above results: in women, the odds ratios (95 % CI) for fractures in mid-childhood famine exposure was 1.461(1.082,1.973), in late childhood famine exposure was 1.333(1.035,1.718) and in adolescence famine exposure was 1.607(1.239,2.085). However, compared to the age-balanced control cohort, men exposed to famine in early childhood (OR: 1.801, 95 % CI: 1.010,3.211) had a higher risk of fracture.

CONCLUSION

Famine exposure in different life stage has adverse effects on bone health. Famine exposure in not only the period from gestation to infancy, but also childhood and adolescence was associated with an increased risk of osteoporosis, especially in women. Exposure to famine in childhood- (mid and late) and adolescence- life period is associated with fracture in women. But, in men early-childhood famine exposure was only associated with fracture.

The Gestational Effects of Maternal Bone Marker Molecules on Fetal Growth, Metabolism and Long-Term Metabolic Health: A Systematic Review

Fetal exposure in adverse environmental factors during intrauterine life can lead to various biological adjustments, affecting not only in utero development of the conceptus, but also its later metabolic and endocrine wellbeing. During human gestation, maternal bone turnover increases, as reflected by molecules involved in bone metabolism, such as vitamin D, osteocalcin, sclerostin, sRANKL, and osteoprotegerin; however, recent studies support their emerging role in endocrine functions and glucose homeostasis regulation. Herein, we sought to systematically review current knowledge on the effects of aforementioned maternal bone biomarkers during pregnancy on fetal intrauterine growth and metabolism, neonatal anthropometric measures at birth, as well as on future endocrine and metabolic wellbeing of the offspring. A growing body of literature converges on the view that maternal bone turnover is likely implicated in fetal growth, and at least to some extent, in neonatal and childhood body composition and metabolic wellbeing. Maternal sclerostin and sRANKL are positively linked with fetal abdominal circumference and subcutaneous fat deposition, contributing to greater birthweights. Vitamin D deficiency correlates with lower birthweights, while research is still needed on intrauterine fetal metabolism, as well as on vitamin D dosing supplementation during pregnancy, to diminish the risks of low birthweight or SGA neonates in high-risk populations.

The role of prenatal vitamin D on the development of childhood asthma and wheeze: An umbrella review of systematic reviews and meta-analyses

BACKGROUND & OBJECTIVE

It has been suggested that prenatal vitamin D plays a role in the development of childhood asthma and wheeze. Several systematic reviews have been conducted, but the results are inconsistent, and the methodological quality has not been studied. Therefore, the objective of this umbrella review was to assess the internal validity of the evidence base and the evidence for an association between prenatal vitamin D and asthma or wheezing in the offspring.

METHODS

We searched the electronic databases Embase, PubMed, and Cochrane Library for studies on prenatal vitamin D using search words such as vitamin D, 25-hydroxyvitamin D, calcidiol, fetal, and neonatal. The search was conducted in June 2020, and the databases were searched from their date of establishment. We included systematic reviews and/or meta-analyses of experimental and observational studies assessing the association between prenatal vitamin D or asthma and wheeze. We excluded narrative reviews, commentaries, and other umbrella reviews. The methodological quality of systematic reviews was assessed using AMSTAR 2 tool. PROSPERO reg. no. CRD42020151329.

RESULTS

We identified 22 eligible systematic reviews (17 on asthma and 20 on wheeze). Using the AMSTAR 2 quality assessment tool, the methodological quality was rated as critically low in 21 out of 22 systematic reviews, suggesting that previous reviews and meta-analyses did not provide accurate and comprehensive summaries of the included studies and that conclusions reached were potentially flawed. The majority of the included reviews reported that prenatal vitamin D reduces the risk of wheeze in the offspring.

CONCLUSION

Prior to informing public guidelines, high-quality systematic reviews of the current evidence are greatly warranted.

An Infant with Asymptomatic Vitamin D Intoxication: A Prolonged and Sustainable Recovery

Vitamin D intoxication (VDI) usually develops due to inappropriate use of vitamin D in high doses by the families of infants with complaints suggestive of vitamin D deficiency such as delayed teething, knock knees, or delayed walking. We present here an experience of treating an infant with asymptomatic VDI that had a prolonged course of recovery and a sustainable level of vitamin D over a follow-up period of 2.5 years. In our patient, vitamin D started to drop steadily after a month of stopping vitamin D supplements but not to a normal level. It reached an acceptable level only after six months. This case emphasizes the importance of educating parents about the empirical use of vitamin D over the counter, assessing the baseline level of serum vitamin D level prior to initiation of treatment and highlights the value of verifying additional dietary sources of vitamin D or oral supplements in patient's history.

Vitamin D Intoxication and Nephrocalcinosis in a Young Breastfed Infant

Numerous studies were performed assessing the benefits and side effects of vitamin D. Vitamin D helps in regulating the calcium and phosphate metabolism leading to a healthy mineral and bone development. Vitamin D intoxication is an uncommon event that leads to hypercalcemia which can be associated with both immediate and late morbidities that can cause severe renal complications. Here, we present a case of a 4-month-old girl with a history of decreased feed and activity due hypercalcemia and high vitamin D level, which led to nephrocalcinosis. The patient received IV fluids, IV diuretics, methylprednisolone, and bisphosphonate in order to normalize the calcium level in blood. With clear verbal and written instructions for the dosage and administration of vitamin D supplements, as well as clear warnings of the potential risks of overdose, vitamin D intoxication could be an easily avoidable condition.

Prevalence of and factors influencing vitamin D deficiency in paediatric patients diagnosed with cancer at northern latitudes

AIM

To investigate the prevalence of vitamin D deficiency among children with non-haematological malignancies and to explore possible causes of low vitamin D levels among these patients.

METHODS

We performed a cross-sectional study of 458 children diagnosed with solid tumours, brain tumours, non-Hodgkin lymphoma or Hodgkin disease at the University Children's Hospital, Uppsala, Sweden. Serum 25-hydroxyvitamin D and parathyroid hormone levels were measured in samples taken at the time of cancer diagnosis and related to clinical data. Vitamin D deficiency was defined as a 25-hydroxyvitamin D level below 50 nmol/L.

RESULTS

The prevalence rate of vitamin D deficiency among children with non-haematological malignancies was 41%. There was no association between sex or diagnosis and vitamin D status. Vitamin D deficiency was more common among school children than preschool children (51% vs. 24%). Older age, season outside summer, and a more recent calendar year were significant predictors of lower 25-hydroxyvitamin D. There was a significant, albeit weak, negative correlation between 25-hydroxyvitamin D and parathyroid hormone.

CONCLUSION

Vitamin D deficiency is common among children diagnosed with cancer, particularly among school-aged children diagnosed outside summer. The prevalence appears to be increasing, underlining the need for adequate replacement of vitamin D in these patients.

Vitamin D and Vascular Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Vitamin D deficiency has been identified as a potential risk factor for a number of diseases unrelated to the classical skeletal pathophysiology, such as cancer and CVD, but the effects of vitamin D supplementation are less clear. Purpose of this narrative review is to discuss the evidence suggesting an association between vitamin D status and CVD as well as the results of supplementation studies. Vitamin D deficiency has been associated with CVD risk factors such as hypertension, dyslipidemia and diabetes mellitus as well as with cardiovascular events such as myocardial infarction, stroke and heart failure. While vitamin D deficiency might contribute to the development of CVD through its association with risk factors, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells. Moreover, vitamin D has been shown to affect inflammation, cell proliferation and differentiation. While observational studies support an association between low plasma vitamin D levels and increased risk of CVD, Mendelian randomization studies do not support a causal association between the two. At present, high quality randomized trials do not find evidence of significant effects on CVD endpoints and do not support supplementation of vitamin D to decrease CVD events.

Prevalence and Predictors of Vitamin D Inadequacy: A Sample of 2,547 Patients in a Mediterranean Country

Background The aim of this retrospective study was to identify prevalence and risk factors for vitamin D inadequacy in a sunny Mediterranean country. Methods Results of 2,547 patients aged 19 to >60 years were included in this study. Data were derived from the laboratory database at Rafik Hariri University Hospital, Beirut, Lebanon, over a period of two years (2016-2017). Data included patient's age, gender, date of test, and vitamin D level. Females were questioned through phone call for marital status, parity, and veiling. Results The prevalence of vitamin D inadequacy was 83.5% overall, 86.4% in males, and 82.3% in females. At a cut-off of 20 ng/mL, vitamin D deficiency affected 63% of the studied population. A significant association was observed between vitamin D and age. The highest prevalence (71.2%) was found in females in the age group of 19-39 years, while no significant correlation with age was observed in males. Vitamin D levels were lower in veiled women (mean 25(OH)D = 17.9 ng/mL) compared to non-veiled women, although this difference was not significant. In addition, vitamin D inadequacy does not show a significant association with gender, parity, marital status, and season of the year. Conclusion The high prevalence of vitamin D inadequacy in our study in both males and females of all age groups calls for urgent actions at the national level to increase awareness in the population and to prevent the serious complications of vitamin D deficiency in all patients, especially those who are at a high risk.

Daily vitamin D3 in overweight and obese children and adolescents: a randomized controlled trial

PURPOSE

To assess the efficacy of different doses of vitamin D₃ on serum 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone(iPTH), calcium, phosphorus, and alkaline phosphatase concentrations in overweight and obese school-children.

METHODS

A total of 378 children and adolescents, 6-13 years of age, with age- and sex-specific body mass index(BMI) Z-score ≥ 1(according to the World Health Organization criteria) were allocated to receive 600, 1000, and 2000 IU vitamin D₃/days. 25(OH)D, iPTH, calcium, phosphorus, and alkaline phosphatase concentrations were measured at baseline, 6, and 12 months. In this intention-to-treat analysis, we fitted a linear mixed effect model involving a random effect of participants within treatment groups and fixed effects of dose, time, and their interactions.

RESULTS

Mean(SD) of age and BMI Z-score were 9.3 (1.7) years and 2.55 (0.73), respectively. The median (IQR) for 25(OH)D was 11.5 (8.9), 11.7 (10.5), 12.2 (10.2) ng/mL (28.75, 29.25, and 30.50 nmol/L) at baseline and 23.1 (8.0), 25.6 (8.3), 28.6 (10.4) ng/mL (57.75, 64.00, and 71.50 nmol/L) at the end of 12 months in 600, 1000, and 2000 IU, respectively (p values for dose, time, and the interaction being < 0.0001, < 0.0001,and 0.082, respectively). Prevalence of vitamin D deficiency (< 20 ng/mL) was 80.2, 77.5, and 75.5% in 600, 1000, and 2000 IU groups at baseline, respectively, which decreased to 34, 18.4, and 7.5%, respectively, at 12 months. Patterns of iPTH, calcium, phosphorus, and alkaline phosphatase response over time did not differ significantly among groups (p values = 0.452, 0.670, 0.377, 0.895, respectively).

CONCLUSIONS

Increases in 25(OH)D concentration were found with supplementation of 1000 and 2000 IU, compared with 600 IU/days, whereas there was no evidence of iPTH suppression or change in serum calcium, phosphorus, and alkaline phosphatase among children with excess weight.

High-dose Cholecalciferol Supplementation Reducing Morning Blood Pressure in Normotensive DM1 Patients

BACKGROUND

Vitamin D (VD) deficiency has been related to several endocrine metabolic and cardiovascular diseases. The effect of VD supplementation on blood pressure (BP) in patients with diabetes is controversial.

OBJECTIVE

The aim of this study was to evaluate high-dose vitamin D supplementation effects on blood pressure of normotensive patients with diabetes mellitus 1 (DM1) patients by 24-hour ambulatory blood pressure monitoring (ABPM).

METHODS

We performed a clinical trial including 35 DM1 normotensive patients, who received doses of 4,000 or 10,000 IU/day of cholecalciferol for 12 weeks according to previous VD levels. They underwent 24-hour ABPM, along with glycated hemoglobin, creatine, lipids profile and PCRus dosage before and after VD supplementation.

RESULTS

We found an expressive reduction of systolic and diastolic morning blood pressures (117±14 vs 112±14, p<0,05; 74±9 vs 70±10 mmHg, p<0,05, respectively) with no changes in other pressoric markers. Besides, we noticed a relationship between levels of VD after supplementation and diastolic morning blood pressure (r= -0,4; p<0.05).

CONCLUSION

Our study suggests an association between supplementation of high doses of vitamin D and the reduction of morning blood pressure in normotensive DM1 patients.

High-Dose Vitamin D Supplementation in Pregnancy and Neurodevelopment in Childhood: A Prespecified Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Observational studies have reported an association between high maternal vitamin D levels and improved neurodevelopment in offspring, but no randomized clinical trial (RCT) has investigated these observations.

OBJECTIVE

To determine whether high-dose vitamin D supplementation during pregnancy improves offspring neurodevelopment from birth to age 6 years.

DESIGN, SETTING, AND PARTICIPANTS

This prespecified secondary analysis of a double-blinded, placebo-controlled RCT of high-dose vitamin D3 supplementation vs standard dose during the third trimester of pregnancy was conducted in the unselected prospective mother-child birth cohort at a single-center research unit in Denmark as part of the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC-2010). Participants included pregnant women; women with vitamin D intake greater than 600 IU/d or an endocrine, heart, or kidney disorder, and those who did not speak Danish fluently were excluded. Neurodevelopmental assessments for offspring of these women were performed at ages 0 to 6 years. Children born prematurely (gestational week <37), with low birth weight (<2500 g), or with a neurological disease affecting neurodevelopment were excluded. Data were analyzed from August 2019 to February 2020.

INTERVENTIONS

High-dose (ie, 2800 IU/d) vs standard dose (ie, 400 IU/d) vitamin D3 supplementation from pregnancy week 24 until 1 week after birth.

MAIN OUTCOMES AND MEASURES

The primary outcome of interest was cognitive development assessed at 2.5 years using the Bayley Scales of Infant and Toddler Development. Other neurodevelopmental outcomes included age of motor milestone achievement (Denver Developmental Index and World Health Organization milestone registration), language development (MacArthur-Bates Communicative Development Inventories), general neurodevelopment at age 3 years (Ages and Stages Questionnaire), and emotional and behavioral problems at age 6 years (Strengths and Difficulties Questionnaire).

RESULTS

Among 623 women randomized, 315 were randomized to high-dose vitamin D3 and 308 were randomized to standard dose placebo. A total of 551 children were evaluated from birth to age 6 years, (282 [51.2%] boys; 528 [95.8%] White), with 277 children in the high-dose vitamin D3 group and 274 children in the standard dose group. There was no effect of the high-dose compared with standard dose of vitamin D3 supplementation during pregnancy on offspring achievement of motor milestones (β = 0.08 [95% CI, -0.26 to 0.43]; P = .64), cognitive development (score difference: 0.34 [95% CI, -1.32 to 1.99]; P = .70), general neurodevelopment (median [IQR] communication score: 50 [50-55] vs 50 [50-55]; P = .62), or emotional and behavioral problems (odds ratio, 0.76 [95% CI, 0.53 to 1.09]; P = .14). There was no effect on language development expressed by the word production at 1 year (median [IQR], 2 [0-6] words vs 3 [1-6] words; P = .16), although a decreased word production was apparent at 2 years in children in the high-dose vitamin D3 group (median [IQR], 232 [113-346] words vs 253 [149-382.5] words; P = .02).

CONCLUSIONS AND RELEVANCE

In this prespecified secondary analysis of an RCT, maternal high-dose vitamin D3 supplementation during the third trimester of pregnancy did not improve neurodevelopmental outcomes in the offspring during the first 6 years of life. These findings contribute essential information clarifying the effects of prenatal exposure to vitamin D on neurodevelopment in childhood.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00856947.

Association between vitamin D and cardioprotection in adult patients

OBJECTIVE

To conduct a review of articles which have evaluated the relationship between vitamin D and cardioprotection in adult.

METHODS

A literature search was performed in the Pubmed and Scielo databases. The results were extracted from primary and secondary sources and will be presented in the form of a bibliographic review.

RESULTS

Twenty-three articles were identified from the electronic search that reported on physiological mechanisms relating the vitamin D axis and the cardiovascular system through receptors. Of the ten studies that evaluated the therapeutic effect of vitamin D in cardiovascular diseases, none reported significant results.

CONCLUSION

The articles assessed in this review did not demonstrate a cardioprotective effect of vitamin D, despite the epidemiological correlation of vitamin D deficiency with a higher prevalence of cardiovascular diseases.

Vitamin D and pregnancy outcomes: Overall results of the FEPED study

Vitamin D insufficiency is highly prevalent in children and adults including pregnant women. During pregnancy, maternal vitamin D insufficiency could increase risks of several pregnancy complications and adverse birth outcomes. The FEPED study was designed to assess the effects of maternal vitamin D status in the first trimester during pregnancy on risks of preeclampsia, gestational diabetes mellitus (GDM), preterm birth and small-for-gestational age (SGA) at birth. This observational prospective cohort included 3129 women with a singleton pregnancy between April 2012 and July 2014 in six maternity units in France and Belgium. The aim of this review is to summarize the results of the FEPED study. At the first trimester the mean 25(OH)D concentration was 21.9 ± 10.4 ng/mL and 25(OH)D concentration was <20 ng/mL in 46.5 % of patients. After matching 83 cases of preeclampsia with 319 controls, a significant decrease in the risk of preeclampsia was associated with maternal vitamin D levels ≥ 30 ng/mL in the third trimesters (OR = 0.34; 95 % CI: 0.13-0.86. P = 0.023). In the first trimester, the risk for preeclampsia was decreased in these patients, but did not achieve statistical significance (OR = 0.57 95 % CI, 0.30-1.01; p = 0.09). For the 250 cases with GDM matched with 941 controls, no linear relationship was found between GDM and 25OHD levels in the first trimester of pregnancy. Finally, 2813 pregnant women were included in analyses of risks of preterm and SGA birth. No association was found between low maternal vitamin D levels in the first trimester and the risks of preterm birth (aOR = 1.53; 95 % CI: 0.97-2.43) or SGA (aOR = 1.07; 95 % CI: 0.75-1.54). Further investigation is needed to understand the mechanisms behind the association between vitamin D and birth outcomes.

Weaker bones and white skin as adaptions to improve anthropological "fitness" for northern environments

The vitamin D paradox relates to the lower risk of osteoporosis in people of sub-Saharan African ancestry (Blacks) compared with people of European ancestry (Whites). The paradox implies that for bone health, Blacks require less vitamin D and calcium than Whites do. Why should populations that migrated northward out of Africa have ended up needing more vitamin D than tropical Blacks? Human skin color became lighter away from the tropics to permit greater skin penetration of the UVB light that generates vitamin D. Lack of vitamin D impairs intestinal calcium absorption and limits the amount of calcium that can deposit into the protein matrix of bone, causing rickets or osteomalacia. These can cause cephalopelvic disproportion and death in childbirth. Whiter skin was more fit for reproduction in UV-light restricted environments, but natural selection was also driven by the phenotype of bone per se. Bone formation starts with the deposition of bone-matrix proteins. Mineralization of the matrix happens more slowly, and it stiffens bone. If vitamin D and/or calcium supplies are marginal, larger bones will not be as fully mineralized as smaller bones. For the same amount of mineral, unmineralized or partially mineralized bone is more easily deformed than fully mineralized bone. The evidence leads to the hypothesis that to minimize the soft bone that causes pelvic deformation, a decrease in amount of bone, along with more rapid mineralization of osteoid improved reproductive fitness in Whites. Adaptation of bone biology for reproductive fitness in response to the environmental stress of limited availability of vitamin D and calcium came at the cost of greater risk of osteoporosis later in life.

Variants rs1544410 and rs2228570 of the vitamin D receptor gene and glycemic levels in adolescents from Northeast Brazil

Introduction

Objective: to verify the association of serum concentrations of 25-hydroxyvitamin D and glycemic levels with the genetic variants rs1544410 and rs2228570 of the VDR gene in adolescents from the Northeast region of Brazil. Materials and methods: a cross-sectional epidemiological study with 208 adolescents from public schools in the city of João Pessoa (Paraíba, Brazil) between 15 and 19 years of age. Blood samples were collected for DNA extraction and analysis of polymorphisms rs1544410 and rs2228570, as well as biochemical analyses (25-hydroxyvitamin D, parathyroid hormone, calcium and glycemia). Results: the mean age was 17.7 (± 1.14) years. Half of adolescents had sufficient serum levels of 25-hydroxyvitamin D and the other half had insufficient/deficient vitamin. The most frequent genotypic distribution was bb and Ff and of lesser frequency BB and ff. There was a significant relationship between the genotypes of rs1544410 and glycemia values (p = 0.049) in the relationships between the genotypes BBxbb (p = 0.012) and Bbxbb (p = 0.037); (p = 0.036, OR = 2.15, 95% CI = 1.05-4.41), and in the BB+Bb group analysis when compared to the bb (p = 0.025, OR = 1.89, 95% CI = 1.08-3.29) presented higher risk of glycemia above the median. On the other hand, when Bb+bb was analyzed in relation to BB, adolescents had a greater chance of blood glucose below the median (p = 0.025, OR = 0.66, CI = 0.47-0.95). Conclusion: this study showed a significant relation of glycemia with the distribution of rs1544410 polymorphism genotypes.

A prospective population-based study of gestational vitamin D status and brain morphology in preadolescents

Low vitamin D level during pregnancy has been associated with adverse neurodevelopmental outcomes such as autism spectrum disorders (ASD) in children. However, the underlying neurobiological mechanism remains largely unknown. This study investigated the association between gestational 25-hydroxyvitamin D [25(OH)D] concentration and brain morphology in 2597 children at the age of 10 years in the population-based Generation R Study. We studied both 25(OH)D in maternal venous blood in mid-gestation and in umbilical cord blood at delivery, in relation to brain volumetric measures and surface-based cortical metrics including cortical thickness, surface area, and gyrification using linear regression. We found exposure to higher maternal 25(OH)D concentrations in mid-gestation was associated with a larger cerebellar volume in children (b ​= ​0.02, 95%CI 0.001 to 0.04), however this association did not remain after correction for multiple comparisons. In addition, children exposed to persistently deficient (i.e., <25 ​nmol/L) 25(OH)D concentration from mid-gestation to delivery showed less cerebral gray matter and white matter volumes, as well as smaller surface area and less gyrification at 10 years than those with persistently sufficient (i.e., ≥50 ​nmol/L) 25(OH)D concentration. These results suggest temporal relationships between gestational vitamin D concentration and brain morphological development in children.

Maternal Vitamin D Levels During Pregnancy and Their Effects on Maternal-Fetal Outcomes: A Systematic Review

To synthesize and critically review the current evidence available on maternal vitamin D deficiency and its effects on maternal-fetal outcomes, this study reviewed the maternal-fetal outcomes, including prolonged labour or cesarean delivery, preeclampsia, gestational diabetes, low birth weight and small for gestational age, and preterm birth. An extensive systematic searched was performed in Medline and EMBASE, where a medical subject heading (MeSH) was used with terms "Vitamin D/25(OH)D" and "pregnancy/fetal outcomes"; these terms were combined with "and." In Web of Science and Google Scholar, a key word search was used. Nineteen articles were included for full review. This review found that the current state of the evidence is equivocal for maternal-fetal outcomes such as the risk of prolonged labour and cesarean delivery, gestational diabetes, low birth weight and small for gestational age, and preterm birth. Although some previous studies have found improvement in pregnancy outcomes with sufficient vitamin D levels, others have not shown any association with the aforementioned outcomes. This systematic review also highlights an association between the risk of preeclampsia and maternal vitamin D levels that is found to be consistent among studies.

Association study between CYP24A1 gene polymorphisms and cancer risk

CYP24A1, an essential gene in regulation of vitamin D, has been reported to play an important role in enhancing immune activity and inhibiting tumorigenesis. Previous studies proposed that rs2585428, rs4809960, rs6022999 and rs6068816 in CYP24A1 gene might be greatly associated with cancer risk. To validate the findings, we here investigated the associations of these four polymorphisms and colorectal cancer (CRC) risk in a central Chinese population (426 colon cancer patients, 361 rectal cancer patients and 800 healthy controls). The genotyping was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and confirmed by sequencing. Our results revealed that the rs4809960 and rs6022999 were strongly associated with the CRC risk, especially with the colon cancer risk. Moreover, the analysis of haplotypes consisting of rs2585428(G > A), rs4809960(T > C), rs6022999(A > G) and rs6068816(C > T) indicated that haplotype ATGC significantly decreased the CRC risk, especially the colon cancer risk. Haplotype GCAT significantly increased the CRC risk, especially the rectal cancer risk. However, haplotype ACAC was only found to be associated with increased risk of CRC. To improve the statistical strength, an updated meta-analysis was further performed. The results showed that rs2585428 was associated with cancer risk in Caucasian population, rs4809960 was associated with breast cancer risk in Caucasian population, and rs6022999 was associated with cancer risk in Asian population. Collectively, the rs4809960 and rs6022999 may be the genetic biomarkers for prediction of colon cancer risk in Chinese population, the rs2585428 and rs6022999 may link to cancer susceptibility in Caucasian population and in Asian population respectly.

Maternal 25-hydroxycholecalciferol during lactation improves intestinal calcium absorption and bone properties in sow-suckling piglet pairs

Lower maternal vitamin D status during lactation is a common health problem. The objectives of this study were to investigate the effects of maternal 25-hydroxycholecalciferol (25-OH-D₃) supplementation during lactation on maternal and neonatal bone health in a sow model. 32 Large White × Landrace sows were assigned randomly to one of two diets supplemented with 2000 IU/kg vitamin D₃ (ND) or 50 μg/kg 25-OH-D₃ (25-D). The experiment began on day 107 of gestation and continued until weaning on day 21 of lactation. Maternal 25-OH-D₃ supplementation significantly decreased milk n-6:n-3 PUFA ratio, which supported bone formation of piglets. Supplementation with 25-OH-D₃ altered bone turnover rate of sows and piglets, as evidenced by higher bone-specific alkaline phosphatase (BALP) concentration in serum. 25-D sows had significantly higher bone density and mechanical properties of tibias and femurs than ND sows. Calcium (Ca) absorption rate was higher in 25-D sows than ND sows, which was caused partially by the increased mRNA expressions of renal 1α-hydroxylase (CYP27B1) and duodenal vitamin D receptor (VDR), transient receptor potential vanilloid 6 (TRPV6), and calcium-binding protein D9k (CaBP-D9k). Maternal 25-OH-D₃ supplementation increased tibial and femoral Ca content by up-regulating Ca-related gene expression in kidney (CYP27B1), ileum (VDR and claudin-2), and colon (VDR and CaBP-D9k), thus, activating 1,25-dihydroxyvitamin D₃ [1,25-(OH)₂-D₃]-dependent Ca transport in piglets. In conclusion, improved milk fatty acids and higher mRNA expressions of calcitropic genes triggered by maternal 25-OH-D₃ supplementation would be the potential mechanism underlying the positive effects of 25-OH-D₃ on maternal and neonatal bone health.

The prevalence of hypovitaminosis D and its risk factors in pregnant women and their newborns in the Middle East: A systematic review

BACKGROUND

Pregnant women and newborns are at risk for vitamin D deficiency (VDD). Also, poor health outcomes for pregnant women with VDD are reported in the published literature.

OBJECTIVE

The aim of this systematic review was to estimate the prevalence of hypovitaminosis D and the associated risk factors for hypovitaminosis D in Middle Eastern pregnant women and their newborns.

RESULTS

The prevalence of circulating 25-hydroxyvitamin D (25(OH)D) < 50 nmol/L as a marker of vitamin D status in pregnant women and their newborns was between 24.5-98% and 22-100%, respectively. The prevalence of 25(OH) D < 25 nmol/L in pregnant women and their newborns was over a wide range between 16.7-80% and 22-82%, respectively. Predictors for low maternal and neonatal 25(OH)D concentrations included decreased vitamin D synthesis due to reduced exposure to sunlight and decreased nutritional intake of vitamin D. A predictor of low neonatal 25(OH)D concentrations included maternal vitamin D status and the correlation between vitamin D concentrations in maternal and cord blood.

CONCLUSION

The high prevalence of VDD in the pregnant women of the Middle East underscores the necessity of implementing national prevention and intervention strategies. A clear policy for clinicians and healthcare workers is needed for screening and maintaining sufficient vitamin D status during pregnancy.

Prevalence and Determinants of Vitamin D Deficiency Among the Overweight and Obese Singaporeans Seeking Weight Management Including Bariatric Surgery: a Relationship with Bone Health

PURPOSE

Low vitamin D status is prevalent worldwide and has been linked to a variety of pathologies including obesity in adults. The severity of vitamin D deficiency amongst the overweight and obese Singaporeans is not well documented. The purpose of this prospective observational study was to assess the prevalence and determinants of vitamin D deficiency in a multi-ethnic Asian population referred for weight management, including those seeking bariatric surgery.

MATERIALS AND METHODS

This was a cross-sectional study conducted among 111 consecutive subjects referred to a single institution weight management service in Singapore. The data collected included their anthropometric data, body mass index (BMI), body fat percentage, waist circumference, 25-hydroxyvitamin D [25(OH)D] and other bone turnover markers.

RESULTS

The average BMI among the 111 subjects was 40.1 ± 8.2 kg/m² and mean age of 40 ± 10 years. Vitamin D deficiency was found in 75.7% of the population. There was a significant negative association of vitamin D with adiposity markers including BMI (r = - 0.31), body fat percentage (r = - 0.34) and waist circumference (r = - 0.26). Predictors of vitamin D deficiency included age > 50 years, female gender, waist circumference and body fat percentage.

CONCLUSION

Vitamin D deficiency is prevalent among this target population in Singapore regardless of ethnicity. In particular, the elderly, females, those with larger waist circumference and body fat percentage were significantly associated with lower serum 25(OH)D level. Hence, routine screening for the overweight and obese subjects in multi-ethnic Singapore seeking weight management is indicated.

Two cases of fractures in neonates associated with maternofetal vitamin D deficiency

Vitamin D supplementation is essential for the entire population, especially during pregnancy and in the pediatric period. We report two case studies of full-term newborns who presented long-bone fractures associated with severe vitamin D deficiency transmitted to them by their mothers, even though maternal supplementation had been implemented according to the existing recommendations. These observations encourage the investigation of neonatal vitamin D deficiency in the presence of long-bone fractures in the absence of traumatic birth and the necessity of reenforcing the means of prevention and the selection of risk groups in order to adjust vitamin D supplementation during pregnancy individually.

Relação entre vitamina D e cálcio no desenvolvimento do Diabetes Mellitus tipo 1 e 2 - Uma revisão de literatura

A prevalência de obesidade, associada a hábitos alimentares inadequados e sedentarismo tem aumentado a ocorrência Diabetes Mellitus, tornando-se um problema de saúde pública. Perspectivas imediatas na mudança do ambiente para reverter o aumento dos níveis de obesidade não são promissores, e existe uma necessidade de considerar outras opções para prevenir o diabetes. Tem sido apontada uma associação inversa entre os baixos níveis da vitamina D e cálcio com a incidencia do Diabetes Mellitus. Desse modo, a vitamina D e o cálcio têm sido propostos como um possível agente terapêutico para a prevenção e tratamento da doença. O objetivo do estudo foi realizar uma revisão de literatura sobre a influência da vitamina D e do cálcio na fisiopatologia do diabetes mellitus, assim como no controle glicêmico.  Estudos têm mostrado que a vitamina D em conjunto com o cálcio são capazes de reduzirem o risco do desenvolvimento do diabetes mellitus tipo 2, enquanto que a insuficiência de vitamina D e de cálcio pode influenciar negativamente a glicemia. Além disso, nível plasmático de 25(OH)D, tem sido correlacionado com o diagnóstico de Diabetes Mellitus tipo 1. Evidências recentes demonstram que a concentração sérica de vitamina D e do cálcio podem estar relacionados ao diabetes. Entretanto, estudos prospectivos e de intervenção em humanos que comprovem a efetividade de ambos, tanto na prevenção como no tratamento dessa doença, ainda são necessários.

Early life vitamin D depletion alters the postnatal response to skeletal loading in growing and mature bone

There is increasing evidence of persistent effects of early life vitamin D exposure on later skeletal health; linking low levels in early life to smaller bone size in childhood as well as increased fracture risk later in adulthood, independently of later vitamin D status. A major determinant of bone mass acquisition across all ages is mechanical loading. We tested the hypothesis in an animal model system that early life vitamin D depletion results in abrogation of the response to mechanical loading, with consequent reduction in bone size, mass and strength during both childhood and adulthood. A murine model was created in which pregnant dams were either vitamin D deficient or replete, and their offspring moved to a vitamin D replete diet at weaning. Tibias of the offspring were mechanically loaded and bone structure, extrinsic strength and growth measured both during growth and after skeletal maturity. Offspring of vitamin D deplete mice demonstrated lower bone mass in the non loaded limb and reduced bone mass accrual in response to loading in both the growing skeleton and after skeletal maturity. Early life vitamin D depletion led to reduced bone strength and altered bone biomechanical properties. These findings suggest early life vitamin D status may, in part, determine the propensity to osteoporosis and fracture that blights later life in many individuals.

The associations between CYP24A1 polymorphisms and cancer susceptibility: A meta-analysis and trial sequential analysis

PURPOSE

Published data have shown that vitamin D may have a protective effect on cancer development. CYP24A1, the main enzyme responsible for the degradation of active vitamin D, plays an important role in many cancer related cellular processes. Up to now, relationships between CYP24A1 polymorphisms and cancer susceptibility have been widely investigated, whereas the results are inconsistent. The aim of present meta-analysis was to explore the associations between CYP24A1 polymorphisms and cancer susceptibility.

METHODS

We searched on EMBASE, Web of Science, PubMed and China National Knowledge Infrastructure (CNKI) electronic databases (up to July 1, 2017) for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to make the evaluation clear.

RESULTS

Twenty-nine studies published in eight publications involving 20,593 cases and 25,458 controls were included. Five CYP24A1 gene polymorphisms were evaluated: rs2181874, rs2585428, rs4809960, rs6022999, and rs6068816. Our analyses suggested that rs2585428 and rs4809960 polymorphisms were significantly associated with overall cancer risk. Stratification analyses of ethnicity indicated that rs2585428 and rs4809960 polymorphisms decreased the risk of cancer among Caucasians. When studies were stratified by cancer type, our results indicated that rs2585428 significantly decreased the risk of pancreas cancer, while rs4809960 significantly decreased the risk of breast cancer. There were no associations of rs2181874, rs6022999, or rs6068816 with overall cancer risks.

CONCLUSION

Associations between CYP24A1 polymorphisms and cancer risks were examined, and additional multi-center studies with large samples are necessary to validate our results.

Vitamin D Deficiency in Pregnant Ukrainian Women: Effects of Alcohol Consumption on Vitamin D Status

OBJECTIVE

Heavy alcohol consumption can alter vitamin D status; however, the relationships between alcohol consumption and vitamin D concentrations in pregnant women have not been well studied. The aim of this study was to investigate the vitamin D status in a population of alcohol-exposed (N = 180) and low/unexposed control (N = 179) Ukrainian pregnant women.

METHODS

Women who attended prenatal care facilities in 2 regions of Ukraine (Rivne and Khmelnytsky) for a routine prenatal visit were screened for the study. At the time of enrollment (20.4 ± 7.0 weeks of gestation), blood samples and alcohol consumption data (during a typical week around conception and the most recent 2 weeks) were collected. Vitamin D status was assessed by 25-hydroxyvitamin D [25(OH)D] concentrations.

RESULTS

A high prevalence of suboptimal vitamin D status in pregnant Ukrainian women was observed. Overall, 50.1% and 33.4% of the women were classified as vitamin D deficient [25(OH)D < 20 ng/mL] or insufficient [25(OH)D ≥ 20 ng/mL and ≤30 ng/mL], respectively, based on 2011 Endocrine Society guidelines. Alcohol-exposed women had significantly lower 25(OH)D concentrations than low/unexposed women in Spring (p = 0.006) and Winter (p = 0.022). When vitamin D concentrations were grouped into sunny season (Summer + Fall) compared to not sunny season (Winter + Spring), there was a significant ethanol by season interaction (p = 0.0028), with alcohol-drinking women having lower circulating vitamin D compared to low/unexposed women in seasons of low sun availability.

CONCLUSIONS

These data suggest that when vitamin D concentrations are generally low (e.g., during seasons of low sun availability), alcohol consumption during pregnancy has a negative impact on vitamin D status.

Vitamin D Deficiency and its Importance - A Global Problem of Today, Realistic or Not?

Vitamin D, also known as the “sun vitamin” in the literature, has been examined for many years and still arouses researchers’ interest due to the pleiotropic effects achieved in the human body. Because of the influence on mineral homeostasis, the initially observed effects of vitamin D on the prevention and treatment of rickets, have now been extended to a large number of diseases with different aetiologies such as cardiovascular, autoimmune, endocrine, infectious, neurological, malignant and other diseases. Due to the large number of experimental studies in animals and humans, we have exact information about the role of vitamin D in many of these conditions. Reaching an adequate level of 25(OH)D in the human body is a basic requirement for the realization of these effects; 25(OH)D is a metabolic product that reflects the vitamin D status but that does not have any biological activity. The biological activities of vitamin D can occur only after the formation of a second metabolic product, 1,25(OH)2D, in the kidneys. The three main sources of acquiring vitamin D are through food, skin and supplementation. Food is not a rich source of vitamin D; it is clear that the most important influences to achieve an optimal vitamin D status in the human body are vitamin D synthesis at the skin and adequate supplementation intake. An alarming fact is that vitamin D deficiency is detected in an increasing number of people from one day to another in the general world population and that this condition has pandemic dimensions. Introducing the beneficial effects and sources of vitamin D to the general population and to medical experts with adequate supplementation regime can decrease the number of people who are vitamin D deficient.

Comparisons of physical activity, adipokines, vitamin D status and dietary vitamin D intake among adolescents

BACKGROUND

Considering that lifestyle and diet are key factors responsible for the increases in adiposity in youth, it is important to understand how vitamin D, adipokines and markers of glucose metabolism are related to physical activity level (PAL) during growth. The present study aimed to investigate associations between physical activity level, adiponectin/leptin ratio, vitamin D status and dietary vitamin D intake among adolescents.

METHODS

A cross-sectional study was conducted with adolescents aged 14-18 years old who were living in São Paulo, Brazil. Serum 25 hydroxyvitamin D [25(OH)D], adiponectin (A), leptin (L), glucose and insulin were obtained after 12 h of fasting. Dietary calcium and vitamin D intake were measured by 24-h food record, as repeated in 62.6% of the sample. PAL was measured by the International Physical Activity Questionnaire (IPAQ). Pearson's chi-square test, Pearson correlation and linear regression analysis were performed.

RESULTS

A total of 198 subjects, mean (SD) age 16.3 (1.4) years, 51% male, were enrolled in the study. Some 9% of participants were sedentary, 22% were insufficiently active (IA), 51% were active and 18% were very active (VA). The A/L ratio was lower among sedentary/IA subjects [2.2 (4.0) versus 5.6 (12.3); P = 0.01] compared to active/VA subjects. PAL was not associated with vitamin D status or markers of glucose metabolism. Serum 25(OH)D positively associated with vitamin D intake, after adjusting for sex, sun exposure and season of the year in regression analysis (partial r² =0.026, P = 0.02).

CONCLUSIONS

Low PAL was associated with a lower A/L ratio. Vitamin D status was not associated with sun exposure habits, although it was positively correlated with vitamin D intake.

Assessment of vitamin D levels, awareness among Lebanese pharmacy students, and impact of pharmacist counseling

Vitamin D inadequacy, frequently underdiagnosed, affects people of all age groups worldwide. This prospective study aims at determining the percentage of inadequate vitamin D levels among students and evaluating the impact of pharmacist counseling on raising the awareness of the importance of sun exposure and adequate vitamin D intake. A total of 160 university students were recruited. Blood samples were taken to check the vitamin D, calcium, and phosphorous levels. Vitamin D levels ⩽30 ng/mL were defined as inadequate. Scores were given to the questions and aimed at gathering patient knowledge about vitamin D before and after pharmacist counseling. A total of 115 (71.87%) patients had vitamin D levels <30 ng/mL, with a mean vitamin D serum level of 16.80 ± 5.85 ng/mL. The mean level of calcium was 9.51 ± 1.23 mg/dL and, of phosphorus 3.62 ± 0.95 mg/dL. The mean difference in the knowledge score of the recommended daily amount of vitamin D before and after pharmacist counseling was 2.81 versus 5.88 (p < 0.001). Concerning patient education for diseases and drugs that affect vitamin D levels, pharmacist counseling was effective in raising the awareness (p < 0.001). Given that vitamin D inadequacy is linked to many disease progressions, it is important that health professionals provide interventional strategies and education measures to correct inadequate levels in patients of all age groups.

Osteoporosis: An under-recognized public health problem

Over 200 million people suffer from osteoporosis worldwide, which occurs when bone tissues become structurally deteriorated and bone mass becomes fragile, resulting in an increased risk of fracture. This review aims to describe the underlying risk factors and provide guidance on changes in lifestyle for those at risk of developing osteoporosis. It highlights risk factors such as age, sex, genetic background, and other under lying illnesses (factors that are generally “non-modifiable”). Furthermore, it focuses on factors that are dependent on lifestyle and (local) habits (factors that are “modifiable”), such as diet, sunlight exposure, exercise, and medication. Clearly, osteoporosis is a multifactorial disease and multiple of these risk factors can occur simultaneously. Currently, the data available differ greatly between regions and some areas might be affected more seriously than others. This review suggests that this might be due to differing healthcare training systems and suboptimal awareness of osteoporosis. Importantly, osteoporosis and resulting bone fractures represent a significant economic burden for both individuals and the wider society. Therefore, improved awareness of the disease may influence personal habits, reduce suffering, and alleviate the burden on healthcare expenditure.

DNA methylation and the social gradient of osteoporotic fracture: A conceptual model

INTRODUCTION

Although there is a documented social gradient for osteoporosis, the underlying mechanism(s) for that gradient remain unknown. We propose a conceptual model based upon the allostatic load theory, to suggest how DNA methylation (DNAm) might underpin the social gradient in osteoporosis and fracture. We hypothesise that social disadvantage is associated with priming of inflammatory pathways mediated by epigenetic modification that leads to an enhanced state of inflammatory reactivity and oxidative stress, and thus places socially disadvantaged individuals at greater risk of osteoporotic fracture.

METHODS/RESULTS

Based on a review of the literature, we present a conceptual model in which social disadvantage increases stress throughout the lifespan, and engenders a proinflammatory epigenetic signature, leading to a heightened inflammatory state that increases risk for osteoporotic fracture in disadvantaged groups that are chronically stressed.

CONCLUSIONS

Our model proposes that, in addition to the direct biological effects exerted on bone by factors such as physical activity and nutrition, the recognised socially patterned risk factors for osteoporosis also act via epigenetic-mediated dysregulation of inflammation. DNAm is a dynamic modulator of gene expression with considerable relevance to the field of osteoporosis. Elucidating the extent to which this epigenetic mechanism transduces the psycho-social environment to increase the risk of osteoporotic fracture may yield novel entry points for intervention that can be used to reduce individual and population-wide risks for osteoporotic fracture. Specifically, an epigenetic evidence-base may strengthen the importance of lifestyle modification and stress reduction programs, and help to reduce health inequities across social groups.

MINI ABSTRACT

Our conceptual model proposes how DNA methylation might underpin the social gradient in osteoporotic fracture. We suggest that social disadvantage is associated with priming of inflammatory signalling pathways, which is mediated by epigenetic modifications, leading to a chronically heightened inflammatory state that places disadvantaged individuals at greater risk of osteoporosis.

Effect of vitamin D supplementation in the reduce risk of preeclampsia in nulliparous women

Background:

The exact role of vitamin D in the development and severity of preeclampsia is still unclear. The aim of the present study was to investigate the association between vitamin D supplement and preeclampsia in pregnant women.

Materials and Methods:

In this randomized controlled trial, in 2012, 140 nulliparous pregnant women in two groups received supplementation with 600 IU/day of vitamin D or supplementation free of vitamin D at 16 week gestation until the delivery. The main outcomes included the frequency of preeclampsia and subtypes by clinical severity and infant birth weight.

Results:

Mean of maternal age and gestational age at the delivery in all studied subjects were 25 ± 4.1 years and 37.4 ± 3 weeks, respectively, which were not statistically significant between the groups. Preeclampsia was observed in two subjects in case group compared to seven subjects in control group, which was not significant (P-value = 0.09). In case group, subjects with preeclampsia diagnosed as mild preeclampsia and in control group four subjects were mild, and three were severe. No significant differences were noted between the case and control groups in the frequency of preeclampsia subtypes by clinical severity. Infant birth weight in case group who was significantly higher than control group, which was statistically significant between groups (P-value = 0.09).

Conclusion:

In summary, our results demonstrated that vitamin D supplementation during the third trimester of pregnancy; despite the non-significant association between vitamin D supplementation and preeclampsia, reduce the risk of preeclampsia. However, further studies needs to be done.

Genetic polymorphisms in the vitamin D pathway in relation to lung cancer risk and survival

Studies have suggested that vitamin D may have protective effects against cancer development or tumor progression. To search for additional evidence, we investigated the role of genetic polymorphisms involved in the vitamin D pathway in non-small cell lung cancer (NSCLC). We evaluated common genetic polymorphisms associated with the vitamin D pathway in relation to NSCLC in a case-control study of 603 newly diagnosed NSCLC patients and 661 matched healthy controls. Seven single nucleotide polymorphisms (SNPs) were genotyped, the expression of CYP27B1 and CYP24A1 were measured in 153 tumor samples and their associations with genotypes and patient survival were also analyzed. In the case-control comparison, we found SNP rs3782130 (CYP27B1), rs7041 (GC), rs6068816 and rs4809957 (CYP24A1) associated with NSCLC risk. The risk of NSCLC was increased with the number of risk alleles. CYP27B1 and CYP24A1 expression were significantly different between tumor and normal tissues in NSCLC. High CYP27B1 expression was associated with better overall survival, and the expression was different by the rs3782130 genotype. The study suggests that some genetic polymorphisms involved in the vitamin D pathway may associate with NSCLC risk, and one of the polymorphisms (rs3782130) may affect gene expression and patient survival.

Predicted vitamin D status during pregnancy in relation to offspring forearm fractures in childhood: a study from the Danish National Birth Cohort

In a prospective cohort study, the association between maternal vitamin D status during pregnancy and offspring forearm fractures during childhood and adolescence was analysed in 30 132 mother and child pairs recruited to the Danish National Birth Cohort between 1996 and 2002. Data on characteristics, dietary factors and lifestyle factors were collected on several occasions during pregnancy. We analysed the association between predicted vitamin D status, based on a subsample with 25-hydroxyvitamin D (25(OH)D) biomarker measurements (n 1497) from gestation week 25, and first-time forearm fractures among offspring between birth and end of follow-up. Diagnoses were extracted from the Danish National Patient Register. Multivariable Cox regression models using age as the underlying time scale indicated no overall association between predicted vitamin D status (based on smoking, season, dietary and supplementary vitamin D intake, tanning bed use and outdoor physical activity) in pregnancy and offspring forearm fractures. Likewise, measured 25(OH)D, tanning bed use and dietary vitamin D intake were not associated with offspring forearm fractures. In mid-pregnancy, 91 % of the women reported intake of vitamin D from dietary supplements. Offspring of women who took >10 µg/d in mid-pregnancy had a significantly increased risk for fractures compared with the reference level of zero intake (hazard ratios (HR) 1·31; 95 % CI 1·06, 1·62), but this was solely among girls (HR 1·48; 95 % CI 1·10, 2·00). Supplement use in the peri-conceptional period exhibited similar pattern, although not statistically significant. In conclusion, our data indicated no protective effect of maternal vitamin D status with respect to offspring forearm fractures.

Maternal vitamin D₃ supplementation at 50 μg/d protects against low serum 25-hydroxyvitamin D in infants at 8 wk of age: a randomized controlled trial of 3 doses of vitamin D beginning in gestation and continued in lactation

BACKGROUND

Vitamin D supplementation is recommended for breastfed infants. Maternal supplementation beginning in gestation is a potential alternative, but its efficacy in maintaining infant 25-hydroxyvitamin D [25(OH)D] concentration after birth is unknown.

OBJECTIVES

We determined the effect of 3 doses of maternal vitamin D supplementation beginning in gestation and continued in lactation on infant serum 25(OH)D and compared the prevalence of infant serum 25(OH)D cutoffs (>30, >40, >50, and >75 nmol/L) by dose at 8 wk of age.

DESIGN

Pregnant women (n = 226) were randomly allocated to receive 10, 25, or 50 μg vitamin D₃/d from 13 to 24 wk of gestation until 8 wk postpartum, with no infant supplementation. Mother and infant blood was collected at 8 wk postpartum.

RESULTS

At 8 wk postpartum, mean [nmol/L (95% CI)] infant 25(OH)D at 8 wk was higher in the 50-μg/d [75 (67, 83)] than in the 25-μg/d [52 (45, 58)] or 10-μg/d [45 (38, 52)] vitamin D groups (P < 0.05). Fewer infants born to mothers in the 50-μg/d group had a 25(OH)D concentration <30 nmol/L (indicative of deficiency) than infants in the 25- and 10-μg/d groups, respectively (2% compared with 16% and 43%; P < 0.05). Fewer than 15% of infants in the 10- or 25-μg/d groups achieved a 25(OH)D concentration >75 nmol/L compared with 44% in the 50-μg/d group (P < 0.05). Almost all infants (∼98%, n = 44) born to mothers in the 50-μg/d group achieved a 25(OH)D concentration >30 nmol/L. At 8 wk postpartum, mean maternal 25(OH)D concentration was higher in the 50-μg/d [88 (84, 91)] than in the 25-μg/d [78 (74, 81)] or 10-μg/d [69 (66, 73)] groups (P < 0.05).

CONCLUSIONS

Maternal supplementation beginning in gestation with 50 μg vitamin D₃/d protects 98% of unsupplemented breastfed infants against 25(OH)D deficiency (<30 nmol/L) to at least 8 wk, whereas 10 or 25 μg vitamin D/d protects only 57% and 84% of infants, respectively.

No association between 25-hydroxyvitamin D levels and prediabetes in Brazilian patients. A cross-sectional study

CONTEXT AND OBJECTIVE

Several studies have evaluated the role of low 25-hydroxyvitamin D (25OHD3) in the pathogenesis of type 2 diabetes (T2DM) and have presented controversial results. The metabolic processes that culminate in T2DM begin under prediabetic conditions. Our aim was to analyze the association between 25OHD3 and glucose metabolism in individuals who were free from but at elevated risk of diabetes.

DESIGN AND SETTING

Cross-sectional study at a tertiary hospital.

METHODS

Anthropometric and laboratory profiles were determined in patients with one or more of the following risk factors: hypertension; body mass index (BMI) ≥ 25 kg/m2; waist circumference > 80 cm for women and > 94 cm for men; first-degree relatives with diabetes; women with large-for-gestational-age newborns or with gestational T2DM; HDL-cholesterol (high density lipoprotein) < 35 mg/dl; and triglycerides > 250 mg/dl. The patients were divided into two groups: one with prediabetes (abnormal fasting plasma glucose or oral glucose tolerance test) and the other with normal glucose (euglycemic).

RESULTS

There was no statistically significant difference between the prediabetic group (n = 38) and euglycemic group (n = 15) regarding age (66.4 ± 10.6 versus 62.6 ± 9.1 years), gender (52.6 versus 73.3% female) and BMI (30.1 ± 4.61 versus 27.9 ± 4.7 kg/m2). Low serum levels of 25OHD3 were found in both groups, without any statistically significant difference between them (29.1 ± 11.8 versus 26.87 ± 9.2 ng/dl).

CONCLUSION

There was no association between 25OHD3 levels and the clinical or laboratorial variables analyzed.

The impact of vitamin D on fetal and neonatal lung maturation. A systematic review

Respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) are major complications to preterm birth. Hypovitaminosis D is prevalent in pregnancy. We systematically reviewed the evidence of the impact of vitamin D on lung development, surfactant synthesis, RDS, and BPD searching PubMed, Embase, and Cochrane databases with the terms vitamin D AND (surfactant OR lung maturation OR lung development OR respiratory distress syndrome OR fetal lung OR prematurity OR bronchopulmonary dysplasia). Three human studies, ten animal studies, two laboratory studies, and one combined animal and laboratory study were included. Human evidence was sparse, allowing no conclusions. BPD was not associated with vitamin D receptor polymorphism in a fully adjusted analysis. Animal and laboratory studies showed substantial positive effects of vitamin D on the alveolar type II cell, fibroblast proliferation, surfactant synthesis, and alveolarization. These data support the hypothesis of hypovitaminosis D as a frequent, modifiable risk factor of RDS and BPD, which should be tested in randomized controlled trials on pregnant women, those with threatening preterm delivery, or in the preterm neonates. Future experimental and human studies should aim to identify optimal time windows, vitamin D doses, and cut-off levels for 25-hydroxyvitamin D in interventions against RDS, BPD, and later adverse respiratory outcomes.

Vitamin D serum levels are associated with handgrip strength but not with muscle mass or length of hospital stay after hip fracture

OBJECTIVES

The aim of this study was to evaluate the association between serum levels of 25(OH) vitamin D3 with midupper arm muscle circumference (MUAMC), handgrip strength and length of hospital stay (LOS) after hip fracture.

METHODS

In total, 102 consecutive patients with hip fracture over the age of 65 were admitted to the orthopedic unit and prospectively evaluated. All of the patients were treated according to specific protocols depending on the type of fracture. Anthropometric measurements and handgrip strength were performed, and blood samples were taken for serum biochemistry and 25(OH) vitamin D3 analysis within the first 72 h of admission. All of the patients were followed during their hospital stay, and the length of stay was recorded.

RESULTS

Of the patients, two were excluded because of pathologic fractures. In total, 100 patients with a mean age of 80 ± 7 y were included in the analysis. Among these patients, 73% were female, and 37% had vitamin D deficiency. The median LOS was 7 (5-11) d. Patients with vitamin D deficiency had lower handgrip strength in univariate analysis. In the multiple linear regression analysis with robust standard error, serum vitamin D levels adjusted by age and sex were associated with handgrip strength but not with MUAMC and LOS after hip fracture.

CONCLUSIONS

In conclusion, vitamin D serum levels were associated with handgrip strength but not with muscle mass or length of hospital stay after hip fracture.

Maternal vitamin D status and offspring bone fractures: prospective study over two decades in Aarhus City, Denmark

Background

Studies investigating the association between maternal vitamin D status and offspring bone mass measured by dual-energy X-ray absorptiometry (DXA) during childhood have shown conflicting results.

Purpose

We used occurrence of bone fractures up to the age of 18 as a measure reflecting offspring bone mass and related that to maternal vitamin D status.

Methods

The Danish Fetal Origins 1988 Cohort recruited 965 pregnant women during 1988–89 at their 30^th gestation week antenatal midwife visit. A blood sample was drawn and serum was stored, which later was analyzed for the concentration of 25-hydroxyvitamin D (25(OH)D) by the liquid chromatography coupled with a tandem mass spectrometric method (LC-MS/MS). Outcome was diagnosis of first time bone fractures extracted from the Danish National Patient Register.

Results

Vitamin D status was available for 850 women. The median (5^th–95^th percentile) 25(OH)D was 76.2 (23.0–152.1) nmol/l. During follow up 294 children were registered with at least one bone fracture diagnosis. Multivariable Cox regression models using age as the underlying time scale indicated no overall association between maternal vitamin D status and first time bone fractures. However, there was a significantly increased hazard ratio (HR) during childhood for those who had maternal blood drawn in Dec/Jan/Feb compared with Jun/Jul/Aug (HR: 1.75, 95%CI: 1.11–2.74). Adjustment for vitamin D status strengthened this association (1.82, 1.12–2.97), which indicated a potential seasonal impact on offspring fractures independent of maternal vitamin D status. In a sensitivity analysis we found a borderline significant inverse association between continuous concentrations of 25(OH)D and offspring forearm fractures (P = 0.054).

Conclusion

Overall, our results did not substantiate an association between maternal vitamin D status and offspring bone fractures. Further studies on this subject are needed, but the study populations must be large enough to allow for subdivision of fractures.

Vitamin D measured in maternal serum and offspring neurodevelopmental outcomes: a prospective study with long-term follow-up

BACKGROUND

Vitamin D is obtained from dietary sources and synthesized in the skin during exposure to ultraviolet B radiation in sunlight. During pregnancy, vitamin D is transported from mother to fetus through the placenta in the form of 25-hydroxyvitamin D [25(OH)D]. There is evidence that vitamin D influences neuronal differentiation, endocrine functions, and fetal brain growth. Animal studies indicate alterations in the offspring brain as a consequence of vitamin D deficiency during pregnancy. In humans, maternal vitamin D insufficiency has been linked to impaired child language development. Using data from a prebirth cohort with up to 22 years of follow-up, we examined the association of vitamin D status with proxies of offspring neurodevelopmental outcomes. During 1988-1989, pregnant women were recruited for the DaFO88 cohort (n = 965) in Aarhus, Denmark. Maternal concentrations of 25(OH)D were quantified in serum from week 30 of gestation via the LC-MS/MS method (n = 850). Offspring were followed up through national registries until the age of 22 years. We evaluated the association of the maternal concentration of 25(OH)D with offspring neurodevelopmental outcomes defined as first admission diagnosis or prescription of medication for (1) ADHD, (2) depression, and (3) scholastic achievement based on the mean grade on standardized written examinations in the 9th grade (final exams after 10 years of compulsory school in Denmark).

KEY MESSAGES

Maternal concentrations of 25(OH)D were higher compared to current levels (median 76 nmol/l; 5th to 95th percentiles 23-152). There was a direct association between maternal vitamin D status and offspring depression (p(trend) = 0.01); for ADHD there was no association. Scholastic achievement was slightly higher for offspring of mothers with a vitamin D status in the range of >50-125 nmol/l, but this nonlinear association was not statistically significant.

CONCLUSIONS

Our analyses based on biomarker measurement of 25(OH)D from a cohort of 850 pregnant women combined with long-term follow-up showed no support for a beneficial fetal programming effect of vitamin D status with regard to behavioral and affective disorders and scholastic achievement.

Vitamin D induces increased systolic arterial pressure via vascular reactivity and mechanical properties

Background/Aims

The aim of this study was to evaluate whether supplementation of high doses of cholecalciferol for two months in normotensive rats results in increased systolic arterial pressure and which are the mechanisms involved. Specifically, this study assesses the potential effect on cardiac output as well as the changes in aortic structure and functional properties.

Methods

Male Wistar rats were divided into three groups: 1) Control group (C, n = 20), with no supplementation of vitamin D, 2) VD3 (n = 19), supplemented with 3,000 IU vitamin D/kg of chow; 3) VD10 (n = 21), supplemented with 10,000 IU vitamin D/kg of chow. After two months, echocardiographic analyses, measurements of systolic arterial pressure (SAP), vascular reactivity, reactive oxygen species (ROS) generation, mechanical properties, histological analysis and metalloproteinase-2 and -9 activity were performed.

Results

SAP was higher in VD3 and VD10 than in C rats (p = 0.001). Echocardiographic variables were not different among groups. Responses to phenylephrine in endothelium-denuded aortas was higher in VD3 compared to the C group (p = 0.041). Vascular relaxation induced by acetylcholine (p = 0.023) and sodium nitroprusside (p = 0.005) was impaired in both supplemented groups compared to the C group and apocynin treatment reversed impaired vasodilation. Collagen volume fraction (<0.001) and MMP-2 activity (p = 0.025) was higher in VD10 group compared to the VD3 group. Elastin volume fraction was lower in VD10 than in C and yield point was lower in VD3 than in C.

Conclusion

Our findings support the view that vitamin D supplementation increases arterial pressure in normotensive rats and this is associated with structural and functional vascular changes, modulated by NADPH oxidase, nitric oxide, and extracellular matrix components.

Vitamin D supplementation and risk of toxicity in pediatrics: a review of current literature

CONTEXT

Although vitamin D toxicity is rare in children, increased use of vitamin D formulations, re-examination of optimal vitamin D levels, and use of higher doses lend potential for an increased incidence of vitamin D toxicity.

EVIDENCE ACQUISITION

A PubMed search was conducted through May 2013 for cases of vitamin D intoxication and vitamin D trials in pediatrics. Safety data were collected and reviewed.

EVIDENCE SYNTHESIS

A small number of pediatric studies tested vitamin D doses at or above the currently recommended upper tolerable intake. In children and adolescents, vitamin D excess was rare and usually asymptomatic. Recent cases of intoxication relate to errors in manufacturing, formulation, or prescription; involve high total intake in the range of 240,000 to 4,500,000 IU; and present with severe hypercalcemia, hypercalciuria, or nephrocalcinosis. However, mild hypercalcemia and hypervitaminosis using currently recommended doses have been reported in infants with rickets.

CONCLUSIONS

Although rare, cases of vitamin D intoxication that present with dramatic life-threatening symptoms still occur in children. Moreover, recent studies in infants raise a potential need for monitoring vitamin D levels when doses at or above the currently recommended upper range are used. Further studies are needed to clarify these findings. The Drugs and Therapeutics Committee of the Pediatric Endocrine Society suggests obtaining serum 25-hydroxyvitamin D levels in infants and children who receive long-term vitamin D supplementation at or above the upper level intake that is currently recommended.

Association of vitamin D insufficiency with adiposity and metabolic disorders in Brazilian adolescents

OBJECTIVE

The present study aimed to evaluate the frequency of deficiency/insufficiency of vitamin D in adolescents and its relationship to overweight and metabolic disorders.

DESIGN

Cross-sectional study. Nutritional status was assessed by BMI according to WHO recommendations. Dietary intake was evaluated using a 3 d dietary record. The biochemical evaluation comprised measurements of serum lipids, lipoproteins, glucose, insulin, calcidiol (25(OH)D) and parathyroid hormone. Insulin resistance was calculated using the homeostasis model assessment. Body composition and blood pressure were assessed.

SETTING

Fifteen schools (eight public and seven private) in the central city of Juiz de Fora, Brazil.

SUBJECTS

The analysis included a study population of 160 adolescents (seventy-seven eutrophic and eighty-three overweight) aged 15 to 17 years.

RESULTS

Vitamin D deficiency and insufficiency was observed in 1.25 and 70.6 % of adolescents, respectively. Serum 25(OH)D levels were statistically lower in adolescents with weight excess, abdominal obesity, hypercholesterolaemia, higher levels of parathyroid hormone, insulin resistance, hyperinsulinaemia and hypertension (P < 0.05). Lower BMI and waist circumference were observed in the third (highest) tertile of vitamin D intake for all adolescents. The high prevalence of vitamin D insufficiency is primarily nutritional and reflects a low vitamin D intake.

CONCLUSIONS

Our results support the negative association among serum 25(OH)D levels and vitamin D intake with non-skeletal outcomes in Brazilian adolescents. Vitamin D fortification of foods and/or the use of vitamin D supplements need to be considered to raise vitamin D intake in the adolescent population, even in a sunny country like Brazil.

Vitamin D3 dose requirement to raise 25-hydroxyvitamin D to desirable levels in adolescents: results from a randomized controlled trial

Several organizations issued recommendations on desirable serum 25-hydroxy vitamin D [25(OH)D] levels and doses of vitamin D needed to achieve them. Trials allowing the formulation of evidence-based recommendations in adolescents are scarce. We investigated the ability of two doses of vitamin D3 in achieving recommended vitamin D levels in this age group. Post hoc analyses on data from a 1-year double-blind trial that randomized 336 Lebanese adolescents, aged 13 ± 2 years, to placebo, vitamin D3 at 200 IU/day (low dose), or 2000 IU/day (high dose). Serum 25(OH)D level and proportions of children achieving levels ≥ 20 ng/mL and 30 ng/mL were determined. At baseline, mean 25(OH)D was 15 ± 7 ng/mL, 16.4 ± 7 ng/mL in boys, and 14 ± 8 ng/mL in girls, p=0.003, with a level ≥ 20 ng/mL in 18% and ≥ 30 ng/mL in 5% of subjects. At 1 year, mean levels were 18.6 ± 6.6 ng/mL in the low-dose group, 17.1 ± 6 ng/mL in girls, and 20.2 ± 7 ng/mL in boys, p=0.01, and 36.3 ± 22.3 ng/mL in the high-dose group, with no sex differences. 25(OH)D increased to ≥ 20 ng/mL in 34% of children in the low-dose and 96% in the high-dose group, being higher in boys in the low-dose arm only; it remained ≥ 30 ng/mL in 4% of children in the low-dose arm but increased to 64% in the high-dose arm. Baseline 25(OH)D level, body mass index (BMI), and vitamin D dose assigned were the most significant predictors for reaching a 25(OH)D level ≥ 20 ng/mL and 30 ng/mL. A daily dose of 2000 IU raised 25(OH)D level ≥ 20 ng/mL in 96% of adolescents (98% boys versus 93% girls). Dose-response studies are needed to determine in a definitive manner the daily allowance of vitamin D for Middle Eastern adolescents with a similar profile.

Vitamin D in endometriosis: a causative or confounding factor?

OBJECTIVE

The aim of this paper is to review the evidence from studies that evaluated the relationship between vitamin D and endometriosis.

DESIGN

Comprehensive review.

MATERIALS AND METHODS

Systematic literature search in Medline for relevant publications from 1946 until June 2013.

RESULTS

Endometriosis risk may be influenced by dietary vitamin D intake and plasma hydroxyvitamin D concentration. Vitamin D receptor and vitamin D metabolizing enzymes, 24-hydroxylase and 1-α hydroxylase, are found in the normal cycling endometrium and also in the eutopic and ectopic endometrium of women with endometriosis. The endometrium is a target of 1, 25 dihydroxyvitamin D actions through regulation of specific genes and via immunomodulation. The endometrium in endometriosis expresses dysregulation of some vitamin D enzymes and receptors. If vitamin D and its metabolites are implicated in endometriosis-associated infertility, it is likely through interference with HOXA10 gene expression. The Gc2 phenotype of vitamin D binding protein is prevalent in women with endometriosis and may be implicated in its pathogenesis. In a mouse model, Elocalcitol, a VDR-agonist was shown to reduce the development of endometriotic lesions and recurrence.

CONCLUSION

A biological plausibility for a role of vitamin D, as an immunomodulator and anti-inflammatory agent, in the pathogenesis and treatment of endometriosis is suggested in this article, but is difficult to illustrate due to sparse evidence from human studies limited primarily to case-control studies. A significant knowledge gap precludes the establishment of a clear cause-effect relationship. The intriguing leads presented herein need to be investigated further with placebo-controlled supplementation trials.

Investigation on the capability of polysulphone for measuring biologically effective solar UV exposures

Polysulphone (PS) dosimetry is a well-known technique broadly used to assess the erythemally effective solar UV dose received by anatomical sites (personal exposure). We investigate the capability of PS dosimetry to convert doses absorbed by PS badges into biologically effective solar UV exposures taking as examples two relevant effects for human skin: erythema induction and pre-vitamin D3 production. PS calibration curves for erythemal and pre-vitamin D3 were distinctly determined by using an empirical relationship between the biologically effective UV exposures and the PS absorbance change. This relationship is parameterized by a coefficient, distinct for each of the two considered biological effects, multiplying the same cubic polynomial function. It is shown how the multiplying coefficient is related to the ratio between the biologically effective and the PS weighted irradiances which is the prevailing factor affecting the accuracy of the calibration and, consequently, the capability of PS films for measuring biologically effective solar UV exposures. The points addressed in this paper can be extended to other biological effects of interest whose action spectra have some similarity with the PS film response.

Allosteric regulation of the calcium-sensing receptor in obese individuals

We have previously reported that the calcium-sensing receptor (CaSR) plays an important role in modulating lipid metabolism under low calcium conditions. The aim of this study was to identify possible regulators of CaSR and the mechanisms of action of CaSR in obese individuals. Subcutaneous fat samples were obtained from 10 obese and 10 non-obese males undergoing elective abdominal surgery. Visceral fat pads were obtained from 12 obese and 12 non-obese male rats. Serum lipid, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations, as well as the gene and protein expression of CaSR in the white adipose tissue of obese subjects and rats were determined. Serum total calcium, vitamin D, parathyroid hormone (PTH) and amino acid levels in human subjects were measured. Intracellular calcium and cyclic adenosine monophosphate (cAMP) levels in rat adipocytes were measured by laser scanning confocal microscopy and ELISA, respectively. The results revealed that serum triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), TNF-α, IL-6 and PTH levels were significantly higher in the obese individuals versus the controls. By contrast, serum vitamin D and amino acid concentrations were lower in the obese individuals versus the controls. In addition, intracellular calcium levels were higher, while cAMP levels were lower in the obese rat adipocytes compared with the control group. However, the gene and protein expression of CaSR in white adipose tissue did not differ between the obese groups and the controls. Thus, these results suggest that CaSR functions not through its expression, but rather through allosteric regulation in obese individuals.