The urgent need to recommend an intake of vitamin D that is effective

Impact of Vitamin D Deficiency on Mental Health in University Students: A Cross-Sectional Study

Students pursuing a university education are vulnerable to psychological burdens such as depression, anxiety, and stress. The frequency of vitamin D deficiency, on the other hand, is extensively recognized worldwide, and vitamin D regulates various neurological pathways in the brain that control psychological function. Therefore, the goal of this cross-sectional study was to determine the relationship between vitamin D deficiency and psychological burden among university students in Riyadh, Saudi Arabia. During March-May 2021 in Riyadh, a cross-sectional comparative study survey was delivered to university students. The DASS-21 scale was used to determine the severity of the psychological burden. Both univariate and binomial regression analyses were conducted to analyze the level of significance and influence of several factors on the development of psychological burden. The data were analyzed with SPSS-IBM, and a p value of <0.05 was considered significant. Of the 480 students recruited for the study, 287 (59.79%) had a vitamin D deficiency. Significantly (p = 0.048), a high proportion of the vitamin D-deficient students attained a low or moderate GPA compared to the control cohort. The prevalence of depression, anxiety, and stress among the vitamin D-deficient students was 60.35%, 6.31%, and 75.08%, respectively, which was significantly (p < 0.05) different from the control group. The odds of developing depression (OR = 4.96; CI 2.22-6.78; p < 0.001), anxiety (OR = 3.87; CI 2.55-6.59; p < 0.001), and stress (OR = 4.77; CI 3.21-9.33; p < 0.001) were significantly higher in the vitamin D-deficient group. The research shows a strong association between psychological stress and vitamin D deficiency. To promote the mental health and psychological wellbeing of university students, it is critical to create awareness about the adequate consumption of vitamin D. Additionally, university students should be made aware of the likelihood of a loss in academic achievement owing to vitamin D deficiency, as well as the cascade effect of psychological burden.

Determinants and Effects of Vitamin D Supplementation in Postmenopausal Women: A Systematic Review

Hormonal fluctuations, excessive clothing covering, sunscreen use, changes in body fat composition, a vitamin D-deficient diet, and a sedentary lifestyle can all predispose postmenopausal women to vitamin D deficiency. An effective supplementation plan requires a thorough understanding of underlying factors to achieve the desired therapeutic concentrations. The objective of this study was to conduct a systematic review of the predictors that affect vitamin D status in postmenopausal women. From inception to October 2022, we searched MEDLINE, Embase, Web of Science, Scopus, and clinical trial registries. Randomized clinical trials of postmenopausal women taking supplements of vitamin D with serum 25-hydroxyvitamin D (25(OH)D) measurement as the trial outcome were included. Two independent reviewers screened selected studies for full-text review. The final assessment covered 19 trials within 13 nations with participants aged 51 to 78. Vitamin D supplementation from dietary and pharmaceutical sources significantly increased serum 25(OH)D to optimal levels. Lower baseline serum 25(OH)D, lighter skin color, longer treatment duration, and prolonged skin exposure were all associated with a better response to vitamin D supplementation in postmenopausal women.

Randomised trial to determine the effect of vitamin D and zinc supplementation for improving treatment outcomes among patients with COVID-19 in India: trial protocol

INTRODUCTION

Presently, there are few population-level strategies to address SARS-CoV-2 infection except preventive measures such as vaccination. Micronutrient deficiency, particularly vitamin D and zinc deficiency, has been associated with dysregulated host responses, and may play an important role in COVID-19.

METHODS AND ANALYSIS

We have designed a 2×2 factorial, randomised, double-blind, multi-centre placebo-controlled trial to evaluate the effect of vitamin D and zinc on COVID-19 outcomes in Maharashtra, India. COVID-19 positive individuals are recruited from hospitals in Mumbai and Pune. Participants are provided (1) vitamin D3 bolus (180 000 IU) maintained by daily dose of 2000 IU and/or (2) zinc gluconate (40 mg daily), versus placebo for 8 weeks. Participants undergo a detailed assessment at baseline and at 8 weeks, and are monitored daily in hospital or every 3 days after leaving the hospital to assess symptoms and other clinical measures. A final follow-up telephone call occurs 12 weeks post-enrolment to assess long-term outcomes. The primary outcome of the study is to time to recovery, defined as time to resolution of all of fever, cough and shortness of breath. Secondary outcomes include: duration of hospital stay, all-cause mortality, necessity of assisted ventilation, change in blood biomarker levels and individual symptoms duration. Participant recruitment commenced on April 2021.

ETHICS AND DISSEMINATION

Ethical approval was obtained from institutional ethical committees of all participating institutions. The study findings will be presented in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBERS

NCT04641195, CTRI/2021/04/032593, HMSC (GOI)-2021-0060.

Vitamin D supplementation worsens Alzheimer's progression: Animal model and human cohort studies

Vitamin D deficiency has been epidemiologically linked to Alzheimer's disease (AD) and other dementias, but no interventional studies have proved causality. Our previous work revealed that the genomic vitamin D receptor (VDR) is already converted into a non‐genomic signaling pathway by forming a complex with p53 in the AD brain. Here, we extend our previous work to assess whether it is beneficial to supplement AD mice and humans with vitamin D. Intriguingly, we first observed that APP/PS1 mice fed a vitamin D‐sufficient diet showed significantly lower levels of serum vitamin D, suggesting its deficiency may be a consequence not a cause of AD. Moreover, supplementation of vitamin D led to increased Aβ deposition and exacerbated AD. Mechanistically, vitamin D supplementation did not rescue the genomic VDR/RXR complex but instead enhanced the non‐genomic VDR/p53 complex in AD brains. Consistently, our population‐based longitudinal study also showed that dementia‐free older adults (n = 14,648) taking vitamin D₃ supplements for over 146 days/year were 1.8 times more likely to develop dementia than those not taking the supplements. Among those with pre‐existing dementia (n = 980), those taking vitamin D₃ supplements for over 146 days/year had 2.17 times the risk of mortality than those not taking the supplements. Collectively, these animal model and human cohort studies caution against prolonged use of vitamin D by AD patients.

Vitamin D: A Potential Mitigation Tool for the Endemic Stage of the COVID-19 Pandemic?

The impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and associated development of clinical symptoms of COVID-19 have presented an enormous global impact on our health care systems, public health and economy. To date several observational epidemiological studies consistently found that vitamin D deficiency, measured as low levels of circulating 25-hydroxyvitamin D, is associated with cardiovascular diseases, diabetes, certain cancers, autoimmune diseases and many infectious diseases, including acute respiratory infections. Since vitamin D is not merely immunosuppressive but also acts as an immunomodulator in tolerance and homeostasis, many experts have considered a role of vitamin D in the prevalence and severity of immune mediated inflammatory diseases, such as SARS-CoV-2, adding to the evidence of the importance of vitamin D in the immune response against viral respiratory infections and reinforcing the need for targeted vitamin D supplementation, with a focus on high-risk populations and a high-dose supplementation treatment for COVID-19 hospitalized patients. The expected transition to endemicity of SARS-CoV-2 even further corroborates as a potential of vitamin D as an potential mitigation tool for the prevention of COVID-19. The aim of this paper is to analyse the current evidence regarding vitamin D and present a hypothesis of its potential role in the current COVID-19 pandemic and in the future as a potential preventive measurement in public health.

High-dose Vitamin D Supplementation and Improvement in Cognitive Abilities, Insomnia, and Daytime Sleepiness in Adolescent Girls

Introduction:

Vitamin D may affect the modulation of signaling pathways in the central nervous system. We aimed to evaluate the effect of high-dose vitamin D supplementation on neuropsychological functions in female adolescents.

Methods:

We studied the effects of 9 weeks of vitamin D supplementation (50000 IU vitamin D3 [cholecalciferol]/week) on cognitive abilities and sleep disorders in 940 adolescent girls.

Results:

Oral vitamin D supplementation improved cognitive abilities, including memory, inhibitory control, selective attention, decision making, planning, sustained attention, and cognitive flexibility in healthy adolescent girls (P<0.001). The prevalence of subjects with insomnia after intervention fell from 15.0% to 11.3%. Similar results were also found for the prevalence of sleepiness (15.6% reduced to 14.7%), or cases with both insomnia and sleepiness (8.0% reduced to 6.1%; P<0.05).

Conclusion:

High dose of vitamin D can improve cognitive abilities and alleviate insomnia and daytime sleepiness in adolescent girls. Further investigations are required on different population groups (age and gender) to determine the sustainability of these effects. The value of vitamin D therapy in other neurological disorders would also be of research interest.

A Literature Review of the Potential Impact of Medication on Vitamin D Status

In recent years, there has been a significant increase in media coverage of the putative actions of vitamin D as well as the possible health benefits that supplementation might deliver. However, the potential effect that medications may have on the vitamin D status is rarely taken into consideration. This literature review was undertaken to assess the degree to which vitamin D status may be affected by medication. Electronic databases were searched to identify literature relating to this subject, and study characteristics and conclusions were scrutinized for evidence of potential associations. The following groups of drugs were identified in one or more studies to affect vitamin D status in some way: anti-epileptics, laxatives, metformin, loop diuretics, angiotensin-converting enzyme inhibitors, thiazide diuretics, statins, calcium channel blockers, antagonists of vitamin K, platelet aggregation inhibitors, digoxin, potassium-sparing diuretics, benzodiazepines, antidepressants, proton pump inhibitors, histamine H2-receptor antagonists, bile acid sequestrants, corticosteroids, antimicrobials, sulphonamides and urea derivatives, lipase inhibitors, hydroxychloroquine, highly active antiretroviral agents, and certain chemotherapeutic agents. Given that the quality of the data is heterogeneous, newer, more robustly designed studies are required to better define likely interactions between vitamin D and medications. This is especially so for cytochrome P450 3A4 enzyme (CYP3A4)-metabolized medications. Nevertheless, this review suggests that providers of health care ought to be alert to the potential of vitamin D depletions induced by medications, especially in elderly people exposed to multiple-drug therapy, and to provide supplementation if required.

Changes in vitamin D and calcium metabolism markers in patients undergoing adjuvant chemotherapy for breast cancer

BACKGROUND

Changes in calcium metabolism and calcium urinary excretion during chemotherapy have not been thoroughly assessed in patients with early breast cancer (EBC), a population who frequently present vitamin D insufficiency. As hypercalciuria is a classical contra-indication to vitamin D (VD) supplementation, this study evaluated changes in VD and calcium metabolism parameters in patients with EBC undergoing adjuvant chemotherapy (CT).

METHODS

In patients with EBC who received six cycles of adjuvant CT, VD and calcium parameters were monitored at inclusion, and then every 3 weeks, at each CT cycle initiation. The primary endpoint was the percentage of patients showing hypercalciuria during adjuvant CT (between Day 1, Cycle 1 [D1C1] and Day 1, Cycle 6 [D1C6]).

RESULTS

The primary endpoint could be evaluated in 82 patients. Most patients (n = 66, 80.5%) had VD insufficiency (< 30 ng/mL) at baseline. Hypercalciuria was detected in 29 patients (35.4%; 95% CI: 25.6-46.5) between D1C1 and D1C6, but was not clinically significant in any of the affected patients. The percentage of hypercalciuria events was not different between patients with sufficient and insufficient baseline VD levels (34.8% vs. 37.5%), and between patients who received or not VD supplementation (37.5% vs. 34.5%,).

CONCLUSIONS

This comprehensive study on VD and calcium parameter changes in patients with EBC during adjuvant chemotherapy shows that hypercalciuria is a frequent abnormality in this setting, although asymptomatic. Therefore, it should not be considered as a limitation for high dose VD supplementation in this population.

TRIAL REGISTRATION

EudraCT:2014-A01454-43 . Registered 29 august 2016.

Effects of a single dose of vitamin D in septic children: a randomized, double-blinded, controlled trial

Objective

To assess the effects of a single dose of vitamin D on 25-hydroxyvitamin D (25OHD) levels and clinical outcomes in children with vitamin D deficiency (VDD) and sepsis.

Methods

In this randomized, controlled trial, eligible children with VDD and sepsis were assigned to receive one dose of 150,000 IU of cholecalciferol or placebo. Serum concentrations of 25OHD, angiotensin-II (Ang-II), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed at baseline and 8 days after treatment. The cardiovascular Sequential Organ Failure Assessment (cv-SOFA) score, septic shock incidence, duration of ventilation, and mortality were also examined.

Results

One hundred nine participants fulfilled the study requirements. The two groups had comparable baseline characteristics. Ang-II, IL-6, and TNF-α concentrations were all reduced after vitamin D supplementation. Furthermore, the cv-SOFA score (1.76 ± 0.8 vs. 2.3 ± 1.1) and incidence of septic shock (7% vs. 20%) were lower in the treatment group than in the control group. The duration of ventilation and mortality rates did not differ between two groups.

Conclusions

A single dose of vitamin D improved 25OHD levels and the incidence of septic shock in children with VDD and sepsis.

Vitamin D deficiency causing eosinophilic esophagogastroenteritis and ascites: a rare association

A 54-year-old Chinese man presented with ascites for 2 weeks. He had a preceding 2-year history of intermittent dysphagia, lethargy and general malaise. Blood investigations revealed leucocytosis with eosinophilia of 26.5%, whereas paracentesis showed turbid fluid with high protein content (45 g/L) and a high white blood cell count of 5580/µL, predominantly eosinophils (90%). An incidental assay of vitamin D showed a very low level of 13.5 ng/mL. No other cause of ascites was found. Gastroscopy was normal except for duodenitis. However, biopsies from lower oesophagus confirmed the presence of eosinophilic infiltration. Following vitamin D replacement, the patient experienced marked improvement in symptoms of dysphagia within 2 weeks and no recurrence of ascites after 3 months. The reason for the patient's vitamin D deficiency remains unclear. The marked improvement in the patient's health indicates a causative role of vitamin D deficiency in causing eosinophilic esophagogastroenteritis and associated eosinophilic ascites.

Vitamin D and Depression in Women: A Mini-review

Affective-related disorders, including depression, are constantly rising, complicating people’s personal lifestyle increasing disqualification and hospital care. Because of the high intensity of urbanization, our lifestyle and food have altered dramatically in the last twenty years. These food modifications have been associated with scores of depression and other affective-related disorders in urbanized countries with high economic levels. Nutrients imbalance is considered as one of the critical causes enabling the pathophysiological mechanisms for the development of psychiatric disorders. The application of additional nutritional interventions for treatment of mood deteriorations can be beneficial for both the prophylaxis and therapy of affective-related disorders. This paper will review recent research on the relation of Vitamin D levels and the epidemiology of depression in women.

In this paper, we will provide an overview of the results of a variety of different studies taking into account research which both suggests and refutes an association. Based on these findings we will propose important directions for future research in relation to this topic.

Reducing overutilisation of serum vitamin D testing at a tertiary care centre

INTRODUCTION

Testing of 25-hydroxy (25-OH) vitamin D serum levels has increased drastically in recent years and much of it is considered inappropriate based on current guidelines.

METHODS

In consultation with our physician groups (experts and frequent orderers), we modified existing guidelines and implemented a rational policy for 25-OH vitamin D testing and 1,25 dihydroxy (1,25 di-OH) vitamin D testing at a tertiary care centre. A computer decision support tool requiring selection of one of five acceptable testing indications was created for each test as part of a computerised physician order entry system.

RESULTS

As a result of our intervention, we observed a 27% decrease in the average monthly test volume for 25-OH vitamin D from 504±62 (mean±SD) tests per month to 370±33 (p<0.001). 1,25 di-OH vitamin D testing decreased 58% from 71±18 to 30±10 (p<0.001). The departments ordering the tests were similar during the preintervention and postintervention periods, and further audits, patient chart reviews and individualised physician feedback were required to ensure appropriate ordering of 1,25 di-OH vitamin D. The most common ordering reasons selected were malabsorption/dietary concerns (46%) for 25-OH vitamin D and renal failure (42%) for 1,25 di-OH vitamin D.

CONCLUSIONS

Limitations of our computer decision support tool include a dependence on an honour system in selecting the testing indication and an inability to limit ordering frequency. Periodic monitoring of test volumes will be required to ensure adherence to guidelines. Despite these limitations, we have improved appropriate utilisation of these tests and reduced costs by approximately $C60 375 per year.

UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Effect of Vitamin D Supplementation on Inflammatory Markers in Non-Obese Lebanese Patients with Type 2 Diabetes: A Randomized Controlled Trial

BACKGROUND

A low serum 25-hydroxyvitamin D (25(OH) D) concentration has been associated with a higher risk of type 2 diabetes mellitus (T2DM), especially in older people. Our aim in this randomized controlled trial was to evaluate the effect of vitamin D treatment on inflammatory markers in non-obese Lebanese patients with T2DM, living in Beirut, Lebanon.

METHODS

Non-Obese patients with T2DM (n = 88), deficient/insufficient in vitamin D, were randomly assigned into one of two groups-a treatment group receiving 30,000 IU cholecalciferol/week for a period of six months, and a placebo group. Serum concentrations of TNF-α, high-sensitivity C-reactive protein (hs-CRP), and Interleukin-6 (IL-6) were the primary outcomes. A homeostatic model of insulin resistance (HOMA-IR) was assessed, in addition to serum concentrations of fasting blood glucose (FBG), HbA1C, (25(OH) D), and PTH.

RESULTS

The vitamin D group showed higher blood levels of (25(OH) D) (p < 0.0001), and a significant reduction in hs-CRP and TNF-α concentrations (p < 0.0001) compared to placebo. The decrease perceived in IL-6 concentrations was not significant (p = 0.1). No significant changes were seen in FBG (p = 0.9) and HbA1c levels (p = 0.85).

CONCLUSION

Six months of vitamin D supplementation led to a decrease in some inflammatory markers in patients with T2DM. Additional studies with a larger sample and a longer period are advised in this regard. This trial was registered at ClinicalTrial.gov; Identifier number: NCT03782805.

Daily versus stat vitamin D supplementation during pregnancy; A prospective cohort study

BACKGROUND

Despite favorable climatic conditions, vitamin D deficiency (VDD) is widespread in Pakistan. Current study was aimed to evaluate the prevalence of VDD in Pakistani pregnant women and effectiveness of various regimen of Vitamin D supplementation.

METHODOLOGY

This hospital-based prospective cohort study included pregnant women at 12th to 24th weeks of gestation attending Gynae clinic from October 2018 to April 2019. Patients were classified into control and treatment groups (Groups: G1, G2 and G3) according to the dose of vitamin D supplementation. Patients received various regimens of vitamin D including 2000 IU/day (G1), 5000 IU/day (G2) and stat 200000 IU (G3). The levels of vitamin D were measured before and after supplementation. The effectiveness of dosages were compared between and within the groups. Moreover, factors associated with vitamin D sufficiency and insufficiency were ascertained using appropriate statistical methods.

RESULTS

Among 281 pregnant women (mean age: 28.22 ± 4.61 years), VDD was prevalent in 47.3% cases. Vitamin D supplementation caused significant rise in the levels 25(OH)D in treatment groups, while there was no significant difference in control group. The highest mean increment in vitamin D (23.14 ± 11.18 ng/ml) was observed with dose 5000 IU/day followed by doses 200000 IU stat (21.06 ± 13.73 ng/ml) and 2000 IU/day (10.24 ± 5.65 ng/ml). Vitamin D toxicity was observed in one patient who received 200000 IU stat of vitamin D. The frequency of VDD following the supplementation was 5.7%. Education status, duration of sun exposure and use of sunblock was substantially associated with vitamin D sufficiency in the current study.

CONCLUSION

Our findings underscore the high proportion of VDD among pregnant women in Pakistan. Maternal vitamin D supplementation substantially improved the levels of 25(OH)D. Of three used regimens, the dose of 5000 IU/day is considered safe and equally effective as of 200000 IU stat. Since pregnancy is a time of tremendous growth and physiological changes for mother and her developing fetus with lifelong implications for the child, gestational vitamin D supplementation should be considered to ensure the optimal vitamin D accrual in pregnant women. This study generates the hypothesis that vitamin D supplementation at a dose of 5000 IU/day during pregnancy is superior to the other regimens. However, well-controlled randomized trials are needed to confirm these findings.

Vitamin D and Disease Severity in Multiple Sclerosis-Baseline Data From the Randomized Controlled Trial (EVIDIMS)

Objective: To investigate the associations between hypovitaminosis D and disease activity in a cohort of relapsing remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS) patients.

Methods: In 51 RRMS and 2 CIS patients on stable interferon-β-1b (IFN-β-1b) treatment recruited to the EVIDIMS study (Efficacy of Vitamin D Supplementation in Multiple Sclerosis (NCT01440062) baseline serum vitamin D levels were evaluated. Patients were dichotomized based on the definition of vitamin D deficiency which is reflected by a < 30 vs. ≥ 30 ng/ml level of 25-hydroxyvitamin D (25(OH)D). Possible associations between vitamin D deficiency and both clinical and MRI features of the disease were analyzed.

Results: Median (25, 75% quartiles, Q) 25(OH)D level was 18 ng/ml (12, 24). Forty eight out of 53 (91%) patients had 25(OH)D levels < 30 ng/ml (p < 0.001). Patients with 25(OH)D ≥ 30 ng/ml had lower median (25, 75% Q) T2-weighted lesion counts [25 (24, 33)] compared to patients with 25(OH)D < 30 ng/ml [60 (36, 84), p = 0.03; adjusted for age, gender and disease duration: p < 0.001]. Expanded disability status scale (EDSS) score was negatively associated with serum 25(OH)D levels in a multiple linear regression, including age, sex, and disease duration (adjusted: p < 0.001).

Interpretation: Most patients recruited in the EVIDIMS study were vitamin D deficient. Higher 25(OH)D levels were associated with reduced T2 weighted lesion count and lower EDSS scores.

A Potential Linking between Vitamin D and Adipose Metabolic Disorders

Vitamin D has been discovered centuries ago, and current studies have focused on the biological effects of vitamin D on adipogenesis. Besides its role in calcium homeostasis and energy metabolism, vitamin D is also involved in the regulation of development and process of metabolic disorders. Adipose tissue is a major storage depot of vitamin D. This review summarized studies on the relationship between vitamin D and adipogenesis and furthermore focuses on adipose metabolic disorders. We reviewed the biological roles and functionalities of vitamin D, the correlation between vitamin D and adipose tissue, the effect of vitamin D on adipogenesis, and adipose metabolic diseases. Vitamin D is associated with adipogenesis, and vitamin D supplements can reduce the burden caused by metabolic diseases. The review provides new insights and basis for medical therapy on adipose metabolic diseases.

Sunlight, UV Radiation, Vitamin D, and Skin Cancer: How Much Sunlight Do We Need?

Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the ultraviolet B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D₃ which in turn is isomerized by the body's temperature to vitamin D₃. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season, and latitude dramatically affect previtamin D₃ synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency pandemic has other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sensible sunlight for providing all humans with their vitamin D requirement for health.

Current opinion on dietary advice in order to preserve fat-free mass during a low-calorie diet

OBJECTIVES

The loss of fat-free mass (FFM) that occurs during weight loss secondary to low-calorie diet can lead to numerous and deleterious consequences. We performed a review to evaluate the state of the art on metabolic and nutritional correlates of loss of fat free mass during low calorie diet and treatment for maintaining fat free mass.

METHODS

This review included 44 eligible studies. There are various diet strategies to maintain FFM during a low-calorie diet, including adoption of a very low carbohydrate ketogenic diet (VLCKD) and taking an adequate amount of specific nutrients (vitamin D, leucine, whey protein).

RESULTS

Regarding the numerous and various low-calorie diet proposals for achieving weight loss, the comparison of VLCKD with prudent low-calorie diet found that FFM was practically unaffected by VLCKD. There are numerous possible mechanisms for this, involving insulin and the insulin-like growth factor-1-growth hormone axis, which acts by stimulating protein synthesis.

CONCLUSIONS

Considering protein and amino acids intake, an adequate daily intake of leucine (4 g/d) and whey protein (20 g/d) is recommended. Regarding vitamin D, if the blood vitamin D has low values (<30 ng/mL), it is mandatory that adequate supplementation is provided, specifically calcifediol, because in the obese patient this form is recommended to avoid seizure in the adipose tissue; 3 to 4 drops/d or 20 to 30 drops/wk of calcifediol are generally adequate to restore normal 25(OH)D plasma levels in obese patients.

Effect of Vitamin D Supplementation on Bone Turnover Markers During HIV Pre-Exposure Prophylaxis Using Tenofovir Disoproxil Fumarate-Emtricitabine in Men Who Have Sex with Men

Pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) reduces bone mineral density in HIV-uninfected men who have sex with men (MSM). We hypothesized that PrEP with TDF-FTC would increase bone turnover markers (BTMs) at week 24 and that vitamin D supplementation from weeks 24 to 48 would blunt this increase. Participants were from a cohort of 398 MSM and transgender women who received daily TDF-FTC for PrEP. At week 24, a prospective intervention group initiated vitamin D3 4,000 IU daily. Concurrent controls were selected from the cohort who took ≤400 IU/day of vitamin D3 matched by age, race, and body mass index. The primary endpoint was the change in procollagen-I N-terminal propeptide (P1NP) from weeks 24 to 48. Paired t-tests were used to compare changes in BTMs between intervention and controls. Among 48 intervention-control pairs, median age was 33 years. At baseline, 68.9% of the intervention group and 77.3% of controls were vitamin D sufficient (≥20 ng/mL, p = .94). P1NP, C-telopeptide, parathyroid hormone (PTH), and 25-OH vitamin D3 did not increase significantly at week 24. P1NP fell by a mean ± SD of -27.6 ± 49.9 pg/mL from weeks 24 to 48 with vitamin D and -2.5 ± 40.2 pg/mL in controls (p = .01). There were no significant between-group differences in the weeks 24-48 change in C-telopeptide, PTH, or 25-OH vitamin D3. Vitamin D3 supplementation with 4,000 IU/day resulted in a significant reduction in the BTM P1NP compared with controls, suggesting that this intervention has potential to improve bone health during PrEP.

Role of Hypovitaminosis D in the Pathogenesis of Obesity-Induced Insulin Resistance

Obesity and type 2 diabetes have both rapidly increased during the last decades and are continuing to increase at an alarming rate worldwide. Obesity and impaired glucose homeostasis are closely related, and during the last decades of investigation about vitamin D, several clinical and epidemiological studies documented an inverse correlation between circulating vitamin D levels, central adiposity and the development of insulin resistance and diabetes. The insufficient sun exposure and outdoor activities of obese individuals, the storage of vitamin D in adipose tissue, because of its lipophilic properties, and the vitamin D-mediated modulation of adipogenesis, insulin secretion, insulin sensitivity and the immune system, are the main reasons for the close relationship between obesity, glucose homeostasis and hypovitaminosis D. Then objective of this review is to explore the pathophysiological mechanism(s) by which vitamin D modulates glycemic control and insulin sensitivity in obese individuals.

The Vitamin D Receptor Gene Polymorphisms in Asthmatic Children: A Case-Control Study

Background: The association between vitamin D receptor (VDR) polymorphisms and the risk of asthma remains unclear. This study aimed to investigate the effect of VDR gene polymorphisms and VDR mRNA expression levels on respiratory function, nitric oxide levels in expiratory air, and serum vitamin D levels in children with asthma. Materials and Methods: The study included 80 healthy children (control group) and 100 asthmatic children (asthma group) between the age of 5 and 18 years. The VDR genotypes (ApaI, TaqI, and FokI) and VDR mRNA levels were determined in all groups. Results: There was no statistically significant difference in vitamin D levels between the asthma group and the control group (P > 0.05). A significant association was found between both genotype (CC) of the TaqI polymorphism [odds ratio (OR) = 0.2, 95% confidence interval (CI) (0.07-0.5), P = 0.003] and genotype (CA) of ApaI polymorphisms [OR = 0.2, 95% CI (0.07-0.8), P = 0.02], and asthma risk. In addition, when single-nucleotide polymorphism allelic frequencies between asthma and control groups were compared there is no significant association (P > 0.05). When compared to control group, VDR mRNA expression in asthma group decreased in genotypes CC and CA of ApaI and in genotypes TT and TC of TaqI (P < 0.05). Conclusion: The results provide supporting evidence for an association between TaqI and ApaI polymorphisms and asthma susceptibility.

25-OH-vitamin D deficiency identifies poor tumor response in hepatocellular carcinoma treated with transarterial chemoembolization

PURPOSE

Vitamin D is implicated linked to liver cancer and chronic liver diseases, but its association with tumor response in hepatocellular carcinoma (HCC) patients undergoing transarterial chemoembolization (TACE) remains unclear. This study aimed to determine whether vitamin D levels influence tumor response in HCC patients treated with TACE.

METHODS

A total of 58 HCC patients undergoing TACE were enrolled in the study. Serum 25-hydroxyvitamin D (25-OHD) levels were determined at baseline and 1 day after TACE using electrochemiluminescence immunoassay. Response to TACE was evaluated after a 4-6 week interval. Univariate and multivariate analyses with Cox regression model were performed to determine the risk factors associated with tumor response. Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive performance of baseline 25-OHD levels on tumor response in HCC patients undergoing TACE.

RESULTS

43.1% of HCC patients showed 25-OHD deficiency. Baseline 25-OHD level was associated with liver cirrhosis (P = 0.025), vascular invasion (P = 0.031), Barcelona Clinic Liver Cancer stage (P = 0.002) and an alanine aminotransferase increase after TACE (P = 0.021). Serum 25-OHD level was significantly decreased 1 day after TACE (P = 0.045). Multiple tumor numbers (P = 0.034) and low baseline 25-OHD levels (P = 0.040) were independently correlated with poor tumor response after TACE. ROC curve analysis showed that baseline 25-OHD levels present better predictive performance for OR in those patients, compared with other current clinical test pointers.

CONCLUSION

Our study suggested that 25-OHD deficiency at baseline is a prognostic indicator for a poor tumor response in hepatocellular carcinoma treated with TACE.

Evaluation and comparison of Vitamin D receptors in periodontal ligament tissue of Vitamin D-deficient chronic periodontitis patients before and after supplementation of Vitamin D3

Background:

Vitamin D, an important hormone required by the body, exerts its biological effects through Vitamin D receptors (VDRs) present on target cells. Vitamin D is ineffective in tissues which lack VDR. Various tissues show the presence of VDRs. However, evidence for the presence of VDRs in human periodontal ligament tissue in fully erupted teeth in adults is lacking. The present study intends to evaluate the presence of VDRs in periodontal ligament (PDL) tissue and assess their response to serum Vitamin D3 levels in chronic periodontic patients.

Materials and Methods:

A total of 19 chronic periodontitis patients were enrolled in the study and tested for serum 25(OH)D3 levels. Deficient patients were supplemented with Vitamin D3. PDL tissue of these patients was isolated after tooth extraction before and after supplementation of Vitamin D3 and analyzed for the presence of VDR in PDL tissue by using enzyme-linked immunosorbent assay.

Results:

All the chronic periodontitis patients were found to be deficient in Vitamin D3. The mean serum 25(OH)D3 level before supplementation was 13.96 ng/mL which significantly increased to 35.12 ng/mL after supplementation of Vitamin D3 for 6 weeks. VDR analysis determined mean VDR conc. in PDL tissue to be -1.443 ng/mL, which increased to 2.38 ng/mL after supplementation. A concentration dependent correlation was seen between serum 25(OH)D3 levels and VDR conc. in PDL tissue after supplementation.

Conclusions:

The study determined Vitamin D Receptors (VDR) in PDL tissue after supplementation of Vitamin D. Thus in addition to the standard treatment modalities, Vitamin D3 supplementation would be an important factor for generation of adequate immune response.

Single high-dose oral vitamin D3 treatment in New Zealand children with inflammatory bowel disease

BACKGROUND

High-dose oral vitamin D (stoss) is a novel treatment in children with inflammatory bowel disease (IBD). Vitamin D supplementation may have benefits in IBD beyond bone health including reduced disease activity and improvements in inflammatory markers. The aim of this study was to retrospectively assess the efficacy, safety and impact on disease activity of single oral high-dose vitamin D3 therapy in New Zealand (NZ) children with IBD and vitamin D deficiency.

METHODS

In this retrospective chart review, children with IBD and vitamin D deficiency [serum 25-OH vitamin D level (25-OHD) <50 nmol/L] in Christchurch, NZ, who were managed with single high-dose vitamin D3 therapy were identified. Measurements of serum 25-OHD, calcium and standard serum inflammatory markers prior to and up to 6 months following stoss therapy were extracted from patient records. Disease activity was also defined using the Pediatric Crohn's Disease (CD) Activity Index (PCDAI) at time points before and 3 months following stoss.

RESULTS

Twenty-eight doses of stoss were given to 23 children, aged 3-16 years. Mean 25-OHD levels increased after stoss therapy from 39 nmol/L (95% CI: 37-42 nmol/L) at baseline to 189 nmol/L (148-231 nmol/L) at 1-2 months (P<0.001). All children with 1 month levels measured achieved 25-OHD >75 nmol/L. One child had a serum calcium of 2.7 (normal range, 2.2 to 2.6 mmol/L) 2 weeks after treatment, which normalized on repeat testing 10 days later. PCDAI scores, mean platelet count, erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) all reduced significantly from baseline to 3 months following stoss therapy.

CONCLUSIONS

Single high-dose oral vitamin D therapy was used successfully and safely to manage vitamin D deficiency in these children with IBD. An improvement in inflammatory markers and disease activity scores also occurred following stoss therapy.

The influences of vitamin D and omega-3 co-supplementation on clinical, metabolic and genetic parameters in women with polycystic ovary syndrome

OBJECTIVE

The aim of this study was to evaluate the effect of the co-administration of vitamin D and omega-3 fatty acid on clinical, metabolic and genetic parameters in women with polycystic ovary syndrome (PCOS).

METHODS

This randomized, double-blinded, placebo-controlled clinical trial was conducted on 60 subjects, aged 18-40 years old with PCOS. Subjects were randomly allocated to take either 50,000 IU vitamin D every 2 weeks plus 2000 mg/day omega-3 fatty acid from fish oil (n = 30) or placebo (n = 30) for 12 weeks. Gene expression analysis of inflammatory cytokines was conducted on peripheral blood mononuclear cells (PBMCs) of PCOS women using RT-PCR method.

RESULTS

Vitamin D and omega -3 fatty acid co-supplementation significantly decreased serum total testosterone levels (-0.2 ± 0.5 vs. + 0.1 ± 0.4 ng/mL, P = 0.02) compared with the placebo. In addition, vitamin D and omega-3 fatty acid co-supplementation resulted in a significant improvement in beck depression inventory (-1.4 ± 1.6 vs. -0.5 ± 0.6, P = 0.01), general health questionnaire scores (-4.5 ± 4.3 vs. -1.9 ± 2.3, P = 0.005) and depression anxiety and stress scale scores (-5.0 ± 5.1 vs. -2.3 ± 3.5, P = 0.01) compared with the placebo. Additionally, vitamin D and omega-3 fatty acid co-administration significantly decreased serum high-sensitivity C-reactive protein (hs-CRP) (-1.2 ± 1.9 vs. + 0.1 ± 0.7 mg/L, P = 0.001) and malondialdehyde (MDA) levels (-0.4 ± 0.4 vs. + 0.2 ± 0.6 µmol/L, P < 0.001), and significantly increased plasma total antioxidant capacity (TAC) levels (+ 114.6 ± 122.2 vs. -2.4 ± 168.2 mmol/L, P = 0.003) compared with the placebo. Results of RT-PCR demonstrated that vitamin D and omega-3 fatty acid co-supplementation significantly downregulated gene expression of interleukin-1 (IL-1) (P = 0.03), and upregulated vascular endothelial growth factor (VEGF) (P = 0.004) in PBMCs of subjects with PCOS, when compared with placebo.

CONCLUSIONS

Overall, the co-administration of vitamin D and omega-3 fatty acid for 12 weeks had beneficial effects on mental health parameters, serum total testosterone, hs-CRP, plasma TAC and MDA levels, and gene expression of IL-1 and VEGF among women with PCOS.

Rationale and design of a placebo controlled randomized trial to assess short term, high-dose oral cholecalciferol on select laboratory and genomic responses in African Americans with hypovitaminosis D

Cardiovascular Disease (CVD) and related disorders remain a leading cause of health disparities and premature death for African Americans. Hypovitaminosis D is disproportionately prevalent in African Americans and has been linked to CVD and CVD risk factors including hypertension, diabetes and obesity. Thus, hypovitaminosis D may represent a common pathway influencing CV risk factors in a select subgroup of persons. The purpose of this paper is to report the study design of a prospective eight week prospective double-blind randomized, placebo-controlled trial (n = 330 allocated 2:1 to intervention vs. control) to assess the effect of placebo vs. high-dose oral cholecalciferol (100,000 IU vitamin D3 at baseline and week 2) on 6-week change of select biologic cardiometabolic risk factors (including parathyroid hormone to assess biologic activity, pro-inflammatory/pro-thrombotic/fibrotic markers, insulin sensitivity and vitamin D metabolites) and their relationship to vitamin D administration and modification by vitamin D receptor polymorphisms in overweight, hypertensive African Americans with hypovitaminosis D. Findings from this trial will present insights into potential causal links between vitamin D repletion and mechanistic pathways of CV disease, including established and novel genomic markers.

Vitamin D deficiency and clinical outcomes related to septic shock in children with critical illness: a systematic review

PURPOSE

Low vitamin D blood levels are related to many clinical outcomes in children with critically illness. However, the relationship of it and septic shock has not been systematically analyzed. The objective of this review was to evaluate the effect of vitamin D on septic shock and predict if vitamin D administration can improve prognosis of it.

MATERIALS AND METHODS

Online databases were searched up to June 1st, 2017 for studies on the relation of vitamin D deficiency (VDD) and clinical outcomes on septic shock in children with critical illness. The primary end point was the effect of VDD on occurrence of septic shock. The secondary endpoints were the association of VDD and clinical outcomes related to septic shock. We summarized the strength of association between VDD and each factor on septic shock. Individual factors were defined as strong, moderate, weak, or inconclusive according to the numbers of the article supporting the relation between them.

RESULTS

Eight studies published between 2012 and 2017, for a total of 1367 patients, were included in the final analysis. We extracted eight patient-level factors and among them one showed strong association of VDD and septic shock. Four factors demonstrated moderate or weak strength of evidence for it: nonresolution of shock, catecholamine refractory shock, fluid boluses, vasopressor use. But evidence for the association between VDD and severity of illness, stay of pediatric intensive care unit (PICU), are weak. Most of the articles showed no significant association between VDD and mortality.

CONCLUSIONS

Among critically ill children, VDD might be associated with the occurrence and resolution of septic shock. A larger multicenter trial could conclusively confirm these findings. Further research is also needed to identify vitamin D administration for better outcomes in pediatric patients.

Calcium and vitamin D in human health: Hype or real?

The incidence and prevalence of vitamin D deficiency are increasing worldwide. It is estimated that over 50% of the world's population have low vitamin D (i.e., hypovitaminosis D; serum levels below 30 ng/mL). In vitamin D inadequacy, human physiological systems work inefficiently. In humans, 80% of the vitamin D is synthesized in the presence of ultraviolet rays from sunlight; for the rest, we rely on diet and nowadays, supplements. The latter becomes important when one is exposed to less than optimal amounts of sunlight, inability to generate vitamin D in the skin efficiently, and/or having conditions that lead to decreased intestinal absorption or increased catabolism of vitamin D. The normal serum 25-hydroxyvitamin D [25(OH)D] level is around 30 ng/mL (75 nmol/L) and the optimal range is between 30 and 60 ng/mL (75-150 nmol/L). In 2011, the Institute of Medicine (IOM) suggested that 600IU of vitamin D is adequate for people below age 71 who are not exposed to sunshine. Although this might be relevant to the ambulatory healthy white Caucasians to achieve serum 25(OH)D level of 20 ng/mL, but it is insufficient for other ethnic groups. Moreover, the IOM recommendations are not suitable for those who live outside North America. Vitamin D requirements are higher during adolescence, pregnancy and lactation, and in many other disease conditions. Most clinicians consider 30 ng/mL as the minimum serum level of 25(OH)D necessary to maintain good health. In the absence of sunlight exposure and with daily oral intake of 600IU vitamin D, very few people would reach serum 25(OH)D level above 30 ng/mL. While an additional daily intake of 1000IU of vitamin D are required for people with lighter-skin color, those with darker complexion and the elderly, require a minimum of 2000IU/day to maintain serum 25(OH)D levels over 30 ng/mL; 5000 IU/day supplement is considered as the safe daily upper limit of supplementation. Vulnerable groups such as the disabled and/or house-bound, obese, with gastrointestinal abnormalities and/or malabsorption syndromes, institutionalized people (e.g., nursing homes, prisons, etc.), and pregnant and lactating women need approximately 4000IU per day for optimal physiological activity. Vitamin D is essential for gastrointestinal calcium absorption, mineralization of osteoid tissue and maintenance of serum ionized calcium level. It is also important for other physiological functions, such as muscle strength, neuromuscular coordination, hormone release, subduing autoimmunity, and curtailing the development of certain cancers.

Maternal and early-life vitamin D deficiency enhances allergic reaction in an ovalbumin-sensitized BALB/c mouse model

Background

Recent studies have shown that vitamin D deficiency may contribute to the high prevalence of food allergy but the underlying mechanisms are far from clear.

Objective

The present study was designed to investigate the effect of maternal and early-life vitamin D deficiency in the development of food allergy.

Design

BALB/c mice were treated with ovalbumin (OVA) to trigger allergic reactions, under vitamin D-deficient (by maternal and early-life feeding of vitamin D deprived chow diet) or vitamin D-sufficient conditions.

Results

Increased occurrence and severity of allergic diarrhea as well as decreased rectal temperature were observed after OVA sensitization. For vitamin D deficiency groups, OVA-specific IgE and IL-4 levels were significantly increased, while IFN-γ levels were unchanged. Vitamin D deficiency also attenuated the structure of small intestinal villi and decreased the expression of the tight junction protein between adjacent epithelial cells and the percentages of CD4⁺CD25⁺Foxp3⁺Treg cell in spleen and mesenteric lymph nodes.

Conclusions

Maternal and early-life vitamin D deficiency have notable influence on the susceptibility to food allergy, which may relate with the reduced population of Treg cell and the dysfunction of intestinal epithelial barrier.

Lactase persistence may explain the paradoxical findings of high vitamin D concentrations in Europeans living in areas of low UV-B irradiation

BACKGROUND/OBJECTIVES

Vitamin D has a critical role in skeletal health and maintaining serum calcium levels. Calcium is needed for a variety of cellular and metabolic processes in the body. Large amounts of vitamin D can be produced in the skin when exposed to UV-B radiation. It is therefore a paradox that in Europe, Caucasians living in higher latitude countries, such as Scandinavia and Iceland, have higher serum vitamin D compared with those living in lower latitude. In a recent study of adult-type lactase persistence (LP), it was shown that Caucasian of European descent, who carried the C-13910T LP allele, had higher levels of total serum 25-hydroxyvitamin D compared with those who were lactase non-persistent. This was attributed to higher consumption of dairy. We postulated that the distribution of the LP C-13910T allele in Caucasian populations may explain the vitamin D concentration pattern seen in Europe.

SUBJECTS/METHODS

Baseline mean total serum 25 hydroxyvitamin D concentration from a clinical trial of post-menopausal women with osteoporosis was correlated to published LP frequencies in European populations.

RESULTS

In multiple regression analysis, mean total serum 25 hydroxyvitamin D concentrations in both winter and summer were in turn correlated to LP phenotype frequency (winter: r² = 0.51, p < 0.05; summer: r² = 0.4, p < 0.05).

CONCLUSIONS

High frequency of LP in northern Europe may explain high mean total serum 25 hydroxyvitamin D concentrations despite low UV-B radiation exposure.

Effect of an vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients - a randomized controlled trial: study protocol

BACKGROUND

Depression is a significant health and economic burden worldwide affecting not only adults but also children and adolescents. Current treatment options for this group are scarce and show moderate effect sizes. There is emerging evidence that dietary patterns and specific nutritional components might play a role in the risk for developing depression. This study protocol focusses on the role of vitamin D which is for long known to be relevant for calcium and phosphorous homeostasis and bone health but might also impact on mental health. However, the assessment of the vitamin D status of depressed juvenile patients, or supplementation of vitamin D is currently not part of routine treatment. Controlled intervention studies are indispensable to prove whether a vitamin D deficiency ameliorates depressive symptoms.

METHODS/DESIGN

This double blinded, randomized controlled trial will enroll 200 inpatients from a child and adolescent psychiatric department with a vitamin D deficiency defined by a 25(OH)-vitamin D-level < 30 nmol/l (12 ng/ml) and a Beck Depressions Inventory (BDI-II) score > 13 (indicating at least: mild depression). Upon referral, all patients will be screened, checked for inclusion criteria, and those eligible will be randomized after written consent into a supplementation or placebo group. Both study-arms will receive treatment-as-usual for their psychiatric disorder according to established clinical guidelines. The participants of the vitamin D supplementation group will receive 2640 I.E. vitamin D3 q.d. for 28 days in accordance with best practice in pediatric endocrinology. We hypothesize that delaying supplementation of vitamin D in the placebo arm will affect the treatment success of the depressive symptomatology in comparison to the vitamin D supplementation group. Patients will be enrolled for a period of 28 days based on the mean length of hospitalization of juveniles with depression.

DISCUSSION

Randomized controlled trials in children and adolescents with depression are needed to elucidate the role of a vitamin D deficiency for mental disorders and to investigate the relevance of a routine assessment and supplementation of vitamin D deficits.

TRIAL REGISTRATION

DRKS00009758, 16/06/2016 (retrospectively registered).

Postpartum depression and vitamin D: A systematic review

Postpartum depression (PPD) is a prevalent mood disorder estimated to affect 20%-40% of women worldwide after childbirth. In recent studies, the effect of vitamin D on prevention of mood disorders and depression has been investigated, but it is still unclear how vitamin D may affect PPD. The evidence on the relevance between vitamin D deficiency and PPD is inconsistent, and assessment of the recent literature has not previously been carried out. Moreover, there are few clinical studies on PPD and vitamin D supplementation. Five studies have so far assessed the relationship between the levels of vitamin D and PPD. Findings from cohort studies suggest that vitamin-D deficiency is related to the incidence of PPD and vitamin D may play a significant role in the recovery of women with PPD, but it is uncertain whether these actions are the effect of vitamin D on the function of hypothalamic-pituitary-adrenal (HPA) axis, the levels of estradiol, serotonin, pro-inflammatory cytokines, and/or of other mechanisms involved in PPD.

The role of vitamin D in adipogenesis

Vitamin D, a secosteroid predominately obtained by endogenous production, has in recent years been linked to obesity and its comorbidities. The purpose of this review is to draw conclusions from animal and human studies on the effects of vitamin D on adipogenesis to identify the molecular links between vitamin D and obesity. The information presented herein was obtained from 4 databases (PubMed, CINAHL, Cochrane Library, Scopus) using predefined search terms, as well as research literature and other reviews. The effects of vitamin D on adipogenesis have been researched in several animal models, and the majority of these studies suggest vitamin D plays an inhibitory role in adipogenesis. Studies into vitamin D status and obesity in humans are limited, with the majority being observational epidemiological studies that provide no conclusions on cause and effect or clear links on the molecular mechanisms. The few cell culture and supplementation studies that have investigated adipogenesis in human cells indicate that, in contrast to findings from rodent studies, vitamin D is proadipogenic. There is insufficient evidence to determine whether 1) vitamin D deficiency is associated with a lean or obese phenotype, 2) vitamin D deficiency is a consequence of obesity, or (3) the effects of vitamin D on fat tissue are due to interactions with calcium.

Vitamin D supplementation during pregnancy: Improvements in birth outcomes and complications through direct genomic alteration

Pregnancy represents a time of rapid change, including dramatic shifts in vitamin D metabolism. Circulating concentrations of the active form of vitamin D-1,25(OH)2D skyrocket early in pregnancy to levels that would be toxic to a nonpregnant adult, signaling a decoupling of vitamin D from the classic endocrine calcium metabolic pathway, likely serving an immunomodulatory function in the mother and her developing fetus. In this review, we summarize the unique aspects of vitamin D metabolism and the data surrounding vitamin D requirements during this important period. Both observational and clinical trials are reviewed in the context of vitamin D's health effects during pregnancy that include preeclampsia, preterm birth, and later disease states such as asthma and multiple sclerosis. With enhanced knowledge about vitamin D's role as a preprohormone, it is clear that recommendations about supplementation must mirror what is clinically relevant and evidence-based. Future research that focuses on the critical period(s) leading up to conception and during pregnancy to correct deficiency or maintain optimal vitamin D status remains to be studied. In addition, what effects vitamin D has on genetic signatures that minimize the risk to the mother and her developing fetus have not been elucidated. Clearly, while there is much more research that needs to be performed, our understanding of vitamin D requirements during pregnancy has advanced significantly during the last few decades.

New insights into the vitamin D requirements during pregnancy

Pregnancy represents a dynamic period with physical and physiological changes in both the mother and her developing fetus. The dramatic 2–3 fold increase in the active hormone 1,25(OH)₂D concentrations during the early weeks of pregnancy despite minimal increased calcium demands during that time of gestation and which are sustained throughout pregnancy in both the mother and fetus suggests an immunomodulatory role in preventing fetal rejection by the mother. While there have been numerous observational studies that support the premise of vitamin D's role in maintaining maternal and fetal well-being, until recently, there have been few randomized clinical trials with vitamin D supplementation. One has to exhibit caution, however, even with RCTs, whose results can be problematic when analyzed on an intent-to-treat basis and when there is high non-adherence to protocol (as if often the case), thereby diluting the potential good or harm of a given treatment at higher doses. As such, a biomarker of a drug or in this case “vitamin” or pre-prohormone is better served. For these reasons, the effect of vitamin D therapies using the biomarker circulating 25(OH)D is a far better indicator of true “effect.” When pregnancy outcomes are analyzed using the biomarker 25(OH)D instead of treatment dose, there are notable differences in maternal and fetal outcomes across diverse racial/ethnic groups, with improved health in those women who attain a circulating 25(OH)D concentration of at least 100 nmol·L⁻¹ (40 ng·mL⁻¹). Because an important issue is the timing or initiation of vitamin D treatment/supplementation, and given the potential effect of vitamin D on placental gene expression and its effects on inflammation within the placenta, it appears crucial to start vitamin D treatment before placentation (and trophoblast invasion); however, this question remains unanswered. Additional work is needed to decipher the vitamin D requirements of pregnant women and the optimal timing of supplementation, taking into account a variety of lifestyles, body types, baseline vitamin D status, and maternal and fetal vitamin D receptor (VDR) and vitamin D binding protein (VDBP) genotypes. Determining the role of vitamin D in nonclassical, immune pathways continues to be a challenge that once answered will substantiate recommendations and public health policies.

Implications of the nutrition transition for vitamin D intake and status in Aboriginal groups in the Canadian Arctic

Aboriginal Canadians have low intakes of vitamin D and are shifting away from consumption of traditional foods. Higher body mass index, skin pigmentation, and geographic latitude of residence further predispose Canadian Aboriginal populations to low vitamin D status. Low vitamin D status could compromise bone health and other health outcomes. Studies assessing vitamin D status of different Aboriginal groups are limited. The aim of this review is to examine the literature on vitamin D status and intakes of Canadian Aboriginal populations living in the Arctic. PubMed was searched for relevant articles published from 1983 to 2013. The prevalence of 25-hydroxy vitamin D deficiency ranged from 13.9% to 76.0% among children and adults in the summer. Furthermore, mean vitamin D intakes among all age groups were below the estimated average requirement. As vitamin D deficiency has been recently associated with chronic diseases, and Aboriginal populations living in the Arctic are at high risk for low vitamin D status, their vitamin D status should be assessed regularly across seasons.

Modulation of inflammatory and immune responses by vitamin D

Vitamin D (VitD) is a prohormone most noted for the regulation of calcium and phosphate levels in circulation, and thus of bone metabolism. Inflammatory and immune cells not only convert inactive VitD metabolites into calcitriol, the active form of VitD, but also express the nuclear receptor of VitD that modulates differentiation, activation and proliferation of these cells. In vitro, calcitriol upregulates different anti-inflammatory pathways and downregulates molecules that activate immune and inflammatory cells. Administration of VitD has beneficial effects in a number of experimental models of autoimmune disease. Epidemiologic studies have indicated that VitD insufficiency is frequently associated with immune disorders and infectious diseases, exacerbated by increasing evidence of suboptimal VitD status in populations worldwide. To date, however, most interventional studies in human inflammatory and immune diseases with VitD supplementation have proven to be inconclusive. One of the reasons could be that the main VitD metabolite measured in these studies was the 25-hydroxyVitD (25OHD) rather than its active form calcitriol. Although our knowledge of calcitriol as modulator of immune and inflammatory reactions has dramatically increased in the past decades, further in vivo and clinical studies are needed to confirm the potential benefits of VitD in the control of immune and inflammatory conditions.

Vitamin D and asthma in children: A systematic review and meta-analysis of observational studies

There is growing literature suggesting a link between Vitamin D deficiency and asthma in children, but systematic reviews are lacking. The aim of this study is to evaluate the prevalence of Vitamin D deficiency in asthmatic children and to assess the correlations of Vitamin D levels with asthma incidence, asthma control, and lung functions. PubMed, EMBASE, and Cochrane Library were searched for observational studies on asthma and Vitamin D. Two authors independently extracted data. Meta-analysis was performed using the Review Manager Software. A total of 23 (11 case-control, 5 cohort, and 7 cross-sectional) studies enrolling 13,160 participants were included in the review. Overall, Vitamin D deficiency and insufficiency were prevalent in 28.5% and 26.7% children with asthma, respectively. The mean 25-hydroxyvitamin D (25(OH)D) levels (10 studies) were significantly lower in asthmatic children as compared to nonasthmatic children with a mean difference of -9.41 (95% confidence interval [CI] -16.57, -2.25). The odds ratio of Vitamin D deficiency (eight case-control studies) was significantly higher among asthmatic children as compared to nonasthmatic children (odds ratio 3.41; 95% CI 2.04, 5.69). Correlations between Vitamin D levels and incidence of asthma, lung functions, and control of asthma had mixed results. To conclude, asthmatic children had lower 25(OH)D levels as compared to nonasthmatic children, but the correlations between 25(OH)D and asthma incidence, asthma control, and lung functions were varied. Well-designed randomized controlled trials are required to determine if children with asthma can benefit from Vitamin D supplementation.

Acute Vitamin D₃ Supplementation in Severe Obesity: Evaluation of Multimeric Adiponectin

Obesity predisposes to vitamin D deficiency (VDD) and glucose abnormalities. It is currently debated if vitamin D administration may improve glucose homeostasis by interacting with modulators of insulin sensitivity, such as adiponectin and its oligomers. In a 4-week inpatient study on a metabolic rehabilitation program, consisting of individualized caloric restriction and aerobic physical exercise in obese subjects with VDD, we assessed the acute effects of 600,000 IU cholecalciferol given per os VD group, 12 subjects; body mass index (BMI) 42.7 ± 1.3 kg/m²) or placebo per os (PL group, 12 subjects, BMI 39.8 ± 0.9 kg/m²) on high (HWM-A), medium (MMW-A), and low molecular weight adiponectin (LMW-A), as quantified by western immunoblot (WIB) and ELISA. During the 4-week study, dieting promoted a similar magnitude of weight loss in VD and PL groups. Compared to the PL group, cholecalciferol administration increased 25(OH)Vit D levels (p < 0.001) and promoted a significant increase of HMW-A expression analyzed by WIB (p = 0.02). In parallel, a significant decrease of leptin/HMW-A ratio (p < 0.05), a biomarker of metabolic homeostasis, was observed. During the study, changes of MMW-A and LMW-A occurred independently of cholecalciferol administration, and were likely explained by weight loss. At odds with these findings, the ELISA assessment of adiponectin oligomers showed no modifications in the VD group or PL group. Current findings suggest that acute cholecalciferol administration selectively modifies HMW-A and the leptin/HMW-A ratio.

Vitamin D Status in South Asian Populations - Risks and Opportunities

Human body acquires a significant amount of vitamin D by cutaneous synthesis under the action of sunlight and less is supplied through nutritional sources. Diversified sociocultural and economic determinants have been identified that limit the dietary intake of vitamin D and enough distribution of sunlight to maintain optimal levels of 25-hydroxyvitamin D (25(OH)D). Consequently, the world has witnessed a high prevalence of hypovitaminosis D in resource-limited South Asian countries. The purpose of this review is to provide a South Asian perspective of vitamin D status, critically examining India, Pakistan, Bangladesh, and Sri Lanka, and to shed light on potential determinants (latitude and season, sunshine exposure habits, age, gender, and genetic factors) leading to hypovitaminosis D among a variety of population groups. Literature search was carried out using bibliographic databases "PubMed," "Google Scholar," and "ScienceDirect.com." Serum 25(OH)D level, 20-50 nmol/L, was mainly taken as vitamin D deficiency, and determinants of low serum 25(OH)D concentration of the population under study were also considered. The review concludes that vitamin D deficiency is highly prevalent among South Asian populations and global efforts are needed to overcome hypovitaminosis in the region. In addition, dietary diversification, supplementation and fortification of foods with vitamin D, adequate exposure to sunlight, and consumption of animal foods were suggested as viable approaches to maintain 25(OH)D levels for optimal health.

25(OH)D status: Effect of D3 supplement

Background

Excess adipose tissue may lead to sequestrating of vitamin D, making it less available for use in the body.

Objective

This study determined if overweight or obese individuals (BMI > 25 kg m⁻²) had insufficient (<30 ng mL⁻¹) levels of 25‐hydroxyvitamin D [25(OH)D] and, if so, would serum levels respond to exogenous supplementation.

Methods

Sixty‐three women who were overweight/obese (BMI = 31.07 ± 5.00 kg m⁻²) were randomly assigned in a double‐blind manner to receive 5,000 IU of vitamin D₃ (D₃) (n = 31) or a placebo (PL) (n = 32) daily. Serum 25(OH)D concentrations were measured by finger‐stick analyses at baseline and after 8 weeks of supplementation. Data were analyzed by using a 2 × 2 (group × time) repeated measure multivariate analysis of variance to determine group differences for pre‐values and post‐values (p < 0.05).

Results

On day one of the study, both D₃ and PL groups had insufficient levels of vitamin D (mean ± SD) 24.03 ± 9.78 ng mL⁻¹ and 23.62 ± 9.77 ng mL⁻¹, respectively. After 8 weeks of supplementation, the D₃ group 25(OH)D level rose to a mean of 43.57 ± 10.87 ng mL⁻¹ (p < 0.001) versus the PL group whose 25(OH)D level remained statistically unchanged 24.31 ± 8.84 ng mL⁻¹. Women who were overweight/obese had insufficient vitamin D levels prior to supplementation.

Conclusions

Following supplementation with 5,000 IU of vitamin D₃, all subjects' 25(OH)D levels rose to a sufficient level (≥30 ng mL⁻¹). The findings of this study concur with the Institute of Medicine and Endocrine Society recommendations in that two to three times the daily requirement of vitamin D is required to improve serum vitamin D levels in individuals who are overweight or obese.

Vitamin D Status and Elevated Red Cell Distribution Width in Community-Dwelling Adults: Results from the National Health and Nutrition Examination Survey 2001-2006

OBJECTIVES

Elevated red cell distribution width (RDW) is associated with morbidity and mortality in community-dwelling individuals. Although RDW is traditionally used to diagnose anemia, it may also be a marker of systemic inflammation. Since vitamin D is a potent modulator of inflammatory cytokines our goal was to investigate whether 25-hydroxyvitamin D levels (25OHD) are associated with RDW in non-hospitalized adults.

DESIGN

To investigate this association, we conducted a cross-sectional study. Stepwise multivariable linear and logistic regression models were used to assess the independent association of 25OHD with RDW. Elevated RDW was defined as >14.5%.

SETTING

Nationwide sample of non-hospitalized adults within the United States.

PARTICIPANTS

Individuals from the National Health and Nutrition Examination Survey from 2001-2006.

RESULTS

15,162 individuals comprised the analytic cohort. Mean 25OHD was 24.9 ng/mL (SE 0.4) and the prevalence of elevated RDW was 6.3%. Linear regression analysis, controlling for age, sex, race, mean corpuscular volume, albumin, and neutropenia, demonstrated that 25OHD was inversely associated with RDW (β=-0.01; 95%CI -0.01 to -0.01). Logistic regression analysis, controlling for the same covariates, also demonstrated an inverse association of 25OHD with elevated RDW (OR 0.96; 95%CI 0.94-0.99). Individuals with 25OHD <30 ng/mL were more likely to have elevated RDW (OR 1.65; 95%CI 1.13-2.40) compared to those individuals with levels ≥30ng/mL.

CONCLUSIONS

In a nationwide sample of non-hospitalized adults within the United States, low 25OHD was associated with increased likelihood of elevated RDW. Further studies are needed to determine whether optimizing vitamin D status can reduce the prevalence of elevated RDW, and thereby reduce morbidity and mortality in the general population.

Can Composite Nutritional Supplement Based on the Current Guidelines Prevent Vitamin and Mineral Deficiency After Weight Loss Surgery?

BACKGROUND

Nutritional deficiencies occur after weight loss surgery. Despite knowledge of nutritional risk, there is little uniformity of postoperative vitamin and mineral supplementation. The objective of this study was to evaluate a composite supplement based on the clinical practice guidelines proposed in 2008 regarding vitamin and mineral supplementation after Roux-en-Y gastric bypass. The composite included iron (Fe) and calcium as well.

METHODS

A retrospective chart review of 309 patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) was evaluated for the development of deficiencies in iron and vitamins A, B1, B12, and D. Patients were instructed to take a custom vitamin and mineral supplement that was based on society-approved guidelines. The clinical practice guidelines were modified to include 1600 international units (IU) of vitamin D3 instead of the recommended 800 IU.

RESULTS

The compliant patients' deficiency rates were significantly lower than those of the noncompliant patients for iron (p = 0.001), vitamin A (p = 0.01), vitamin B12 (p ≈ 0.02), and vitamin D (p < 0.0001). Women's menstrual status did not significantly influence the development of iron deficiency.

CONCLUSIONS

Use of a composite based on guidelines proposed by the AACE, TOS, and the ASMBS appears to be effective for preventing iron and vitamins A, B1, B12, and D deficiencies in the LRYGB patients during the first postoperative year. Separation of calcium and Fe does not need to be mandatory. Even with simplification, compliance is far from universal.

A randomized clinical trial comparing 3 different replacement regimens of vitamin D in clinically asymptomatic pediatrics and adolescents with vitamin D insufficiency

BACKGROUND

Pediatric and Adolescent populations both have special needs for vitamin D especially for growing bone. Inadequate vitamin D is defined as 25 (OH) D(25hydroxy vitamin D) < 30 ng/ml.

METHODS

We conducted a randomized, controlled clinical trial from July 2014 over 1 year, aiming to assess the changes in 25 (OH) D and biochemical outcome on calcium and PTH(parathyroid hormone) using 3 different regimens of vitamin D replacement. Initial and 4 month 25 (OH) D, calcium, PTH and 12 month 25 (OH) D levels were assayed. Participants divided into 3 groups: 1) given 400 IU daily, 2) given 45000 IU weekly for 2 months then 400 IU daily, 3) given 2000 IU daily for 3 months then 1000 IU daily.

RESULTS

The results showed significant difference between the 3 groups as regards 25 (OH) D at 4 and 12 months (P < 0.001). Regimens used in group 2 and 3 caused increase in 25 (OH) D after 4 month (median increase is 225% and 200% respectively). 25 (OH) D dropped in group 1 and 2 (median decrease is 42 and 53% respectively) but continued to increase in group 3 (median change is 6%). In group 2 serum calcium median change was 1.2% with few cases of hypercalcuria. 94.9, 76.1 and 7.7 are the percent of vitamin D deficient participants in groups 1, 2 and 3 respectively after 12 months follow up.

CONCLUSION

We advise as a replacement for vitamin D insufficiency, low loading dose with high maintaince dose rather than the opposite to achieve steady increase in serum 25 (OH) D with no hypercalcemic side effects.

Assessment of Adequacy of Supplementation of Vitamin D in Very Low Birth Weight Preterm Neonates: A Randomized Controlled Trial

OBJECTIVES

To compare the effect of 400 IU and 1000 IU vitamin D for 6 weeks in very low birth weight preterm neonates.

DESIGN

Randomized, double-blinded controlled trial in a teaching hospital.

PARTICIPANTS

Fifty very low birth weight preterm neonates.

INTERVENTION

Vitamin D 400 IU/day (Group 1) or 1000 IU/day (Group 2).

OUTCOME MEASURES

Change in serum calcium, phosphate, alkaline phosphatase (ALP), 25-hydroxy vitamin D (25-OHD), parathormone, incidence of skeletal hypomineralization and growth.

RESULTS

After 6 weeks of supplementation, the mean serum calcium and 25-OHD levels were significantly higher (p  <  0.001 each), while ALP and parathormone levels significantly lower (p  <  0.001 each) in group 2. Skeletal hypomineralization was lesser and growth better in group 2.

CONCLUSION

Vitamin D supplementation in a dose of 1000 IU/day is more effective in maintaining serum calcium, phosphate, ALP, 25-OHD and parathormone levels with lower incidence of skeletal hypomineralization and better growth.

Prevalence and predictors of vitamin D deficiency based on maternal mid-gestation and neonatal cord bloods: The Generation R Study

BACKGROUND

Population-based studies have confirmed that the prevalence of vitamin D deficiency is substantial in many societies, and is of particular concern in pregnant women. Vitamin D deficiency during pregnancy is associated with a wide range of adverse maternal and offspring health outcomes. To date, studies of vitamin D deficiency during pregnancy have focused on measurements at one or two time points in isolation. We examined both midgestation and cord blood 25 hydroxyvitamin D (25OHD) concentration and explored the prevalence and correlates of vitamin D deficiency in a large ethnically diverse cohort of pregnant women and their infants in the Netherlands.

METHODS

This study was embedded in the Generation R Study, a population-based prospective cohort from fetal life onwards in Rotterdam, The Netherlands. Using a highly sensitive tandem mass spectroscopy-based assay, we measured 25OHD in 7256 midgestation samples (mean gestation 20.6 weeks) and 5023 neonatal cord blood samples (mean gestation 40.0 weeks). Using a conservative threshold of less than 25nmol/L to define vitamin D deficiency, we examined the prevalence and socio-demographic correlates of vitamin D deficiency in mothers and infants. We also derived a measure of vitamin D deficiency based on the two time points in order to explore persistent vitamin D deficiency in mother-infant pairs.

RESULTS

The prevalence of vitamin D deficiency at midgestation was 26%, while in neonates 46% were deficient. 21% of the mother-infant pairs had persistent vitamin D deficiency (i.e., deficient in maternal and cord samples) and an additional 29% were vitamin D deficient in one of the two samples only. Persistent vitamin D deficiency was strongly associated with non-European ancestry and spring birth.

CONCLUSIONS

A sizeable proportion of women and their neonatal offspring in the Generation R cohort were vitamin D deficient. In light of the large body of evidence linking vitamin D deficiency with adverse health outcomes for pregnant women and their offspring, our findings indicate a large unmet need in this population. In particular, women and infants from non-European ethnic background are at high risk of vitamin D deficiency.