scholarly journals Vitamin D and Infertility: The Evidence

2019 ◽  
Vol 01 (01) ◽  
pp. 31-33 ◽  
Author(s):  
Mark D. Hornstein
Keyword(s):  
Vitamin D ◽  
Animal Studies ◽  
Uv Light ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Success Rates ◽  
Minimal Impact ◽  
Vitamin D Receptors ◽  
Vitamin D Intake ◽  
Vitamin D Levels

Vitamin D is a lipid soluble vitamin synthesized by the skin upon exposure to UV light. Approximately 10–20% of vitamin D comes from dietary sources and 25OH-D is its circulating form. Vitamin D receptors are found in reproductive tissues including ovary, uterus, and endometrium permitting investigators to hypothesize a role for vitamin D in reproduction. Indeed, a number of animal studies provide evidence of vitamin D’s importance in fertility. Studies in humans, however, generally have not supported an effect of vitamin D on fertility outcomes. Several retrospective cohort studies did not demonstrate an association between vitamin D levels and pregnancy. Similarly, one study did not find correlation between anovulatory infertility and vitamin D intake. Very low levels of vitamin D, however, were associated with miscarriage in another study. A large meta-analysis of 11 studies and 2700 women did show an improvement in IVF success rates in those with higher levels of vitamin D. Finally, two small studies on vitamin D supplementation and pregnancy did not show a benefit of increasing vitamin D intake. In conclusion, the literature at best shows a minimal impact of vitamin D on infertility and IVF outcomes.

scholarly journals To Supplement or not to Supplement? The Rationale of Vitamin D Supplementation in Systemic Lupus Erythematosus

2018 ◽  
Vol 12 (1) ◽  
pp. 226-247 ◽  
Author(s):  
Alessandra Nerviani ◽  
Daniele Mauro ◽  
Michele Gilio ◽  
Rosa Daniela Grembiale ◽  
Myles J. Lewis
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Lupus Erythematosus ◽  
Clinical Manifestations ◽  
Vitamin D Supplementation ◽  
Current Evidence ◽  
Systemic Lupus ◽  
Vitamin D Receptors ◽  
Vitamin D Levels

Background: Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease characterised by abnormal activation of the immune system, chronic inflammation and organ damage. Lupus patients are more prone to be vitamin D deficient. However, current evidence is not conclusive with regards to the role played by vitamin D in SLE development, progression, and clinical manifestations. Objective: Here, we will summarise the current knowledge about vitamin D deficiency prevalence, risk factors, molecular effects, and potential pathogenic role in SLE. We will focus on the link between vitamin D deficiency and lupus clinical manifestations, and on the clinical trials assessing the effects of vitamin D supplementation in SLE. Method: A detailed literature search was performed exploiting the available databases, using “vitamin D and lupus/SLE” as keywords. The relevant interventional trials published over the last decade have been considered and the results are reported here. Conclusion: Several immune cells express vitamin D receptors. Thus, an immunomodulatory role for vitamin D in lupus is plausible. Numerous observational studies have investigated the relationship between vitamin D levels and clinical/serological manifestations of SLE with contrasting results. Negative correlations between vitamin D levels and disease activity, fatigue, renal and cardiovascular disease, and anti-dsDNA titres have been described but not conclusively accepted. In experimental models of lupus, vitamin D supplementation can improve the disease. Interventional trials have assessed the potential therapeutic value of vitamin D in SLE, but further larger studies are needed.

scholarly journals Is there a benefit of vitamin D supplementation in deficient children and adolescents suffering from obesity? A meta-analysis

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
M F Nassar ◽  
E K Emam ◽  
M F Allam
Keyword(s):  
Vitamin D ◽  
Children And Adolescents ◽  
Vitamin D Deficiency ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Obese Children ◽  
Intramuscular Dose ◽  
Vitamin D Levels ◽  
Pubmed Search ◽  
Lower Vitamin

Abstract Background and objectives Both childhood obesity and vitamin D deficiency are common in the Middle East. This systematic review/meta-analysis aims to highlight the effect of vitamin D supplementation in deficient children suffering from obesity. Methods Published clinical studies on vitamin D supplementation in obese children and adolescents with vitamin D deficiency were identified through a comprehensive MEDLINE/PubMed search (from July 1966 to November 2017). Outcomes intended after vitamin D supplementation were improvements in vitamin D status, BMI alterations and appetite changes. The inclusion criteria were children aged 2 to 18 years of both sexes in clinical trials that specified the oral and/or intramuscular dose of vitamin D supplementation. Results Ten studies were retrieved, but only six were relevant. First, supplemented obese children and adolescents were compared to non-obese controls; thereafter, supplemented obese children and adolescents were compared to matching obese peers given placebo. Pooled risks from the two studies that evaluated the number of obese and non-obese children and adolescents who improved upon vitamin D supplementation revealed that obesity poses a risk for not benefiting from the vitamin D supplementation regardless of the dose and the duration of supplementation. Pooled results from the six retrieved studies that compared supplemented obese children and adolescents to matching non-obese or obese peers given placebo revealed significantly lower vitamin D levels in obese participants than in non-obese peers. Conclusion Vitamin D levels are significantly lower in obese children and adolescents with obesity, posing a risk for not benefiting from vitamin D supplementation regardless of the dose and duration of supplementation. Our results suggest that only with simultaneous weight adjustment strategies, vitamin D sufficiency would be achieved more effectively. Vitamin D supplementation in deficient children suffering from obesity.

scholarly journals The effect of vitamin D supplementation on survival in patients with colorectal cancer: systematic review and meta-analysis of randomised controlled trials

2020 ◽  
Vol 123 (11) ◽  
pp. 1705-1712 ◽  
Author(s):  
Peter G. Vaughan-Shaw ◽  
Louis F. Buijs ◽  
James P. Blackmur ◽  
Evi Theodoratou ◽  
Lina Zgaga ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Vitamin D ◽  
High Risk ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Risk Of Bias ◽  
Survival Outcomes ◽  
Vitamin D Levels ◽  
Randomised Controlled ◽  
Incident Cases

Abstract Background Low circulating vitamin D levels are associated with poor colorectal cancer (CRC) survival. We assess whether vitamin D supplementation improves CRC survival outcomes. Methods PubMed and Web of Science were searched. Randomised controlled trial (RCTs) of vitamin D supplementation reporting CRC mortality were included. RCTs with high risk of bias were excluded from analysis. Random-effects meta-analysis models calculated estimates of survival benefit with supplementation. The review is registered on PROSPERO, registration number: CRD42020173397. Results Seven RCTs (n = 957 CRC cases) were identified: three trials included patients with CRC at outset, and four population trials reported survival in incident cases. Two RCTs were excluded from meta-analysis (high risk of bias; no hazard ratio (HR)). While trials varied in inclusion criteria, intervention dose and outcomes, meta-analysis found a 30% reduction in adverse CRC outcomes with supplementation (n = 815, HR = 0.70; 95% confidence interval (CI): 0.48–0.93). A beneficial effect was seen in trials of CRC patients (progression-free survival, HR = 0.65; 95% CI: 0.36–0.94), with suggestive effect in incident CRC cases from population trials (CRC-specific survival, HR = 0.76; 95% CI: 0.39–1.13). No heterogeneity or publication bias was noted. Conclusions Meta-analysis demonstrates a clinically meaningful benefit of vitamin D supplementation on CRC survival outcomes. Further well-designed, adequately powered RCTs are needed to fully evaluate benefit of supplementation in augmenting ‘real-life’ follow-up and adjuvant chemotherapy regimens, as well as determining optimal dosing.

scholarly journals Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies

Aging ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 12708-12732 ◽  
Author(s):  
Dingli Song ◽  
Yujiao Deng ◽  
Kang Liu ◽  
Linghui Zhou ◽  
Na Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Vitamin D ◽  
Dose Response ◽  
Observational Studies ◽  
Meta Analysis ◽  
Vitamin D Intake ◽  
Vitamin D Levels

scholarly journals Body Mass Index, Vitamin D, and Type 2 Diabetes: A Systematic Review and Meta-Analysis

Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1182 ◽  
Author(s):  
Shamaila Rafiq ◽  
Per Jeppesen
Keyword(s):  
Systematic Review ◽  
Body Mass Index ◽  
Vitamin D ◽  
Body Mass ◽  
Observational Studies ◽  
Meta Analysis ◽  
Serum Vitamin ◽  
Vitamin D Supplementation ◽  
Serum Vitamin D ◽  
Vitamin D Levels

The deficiency of vitamin D is prevalent all over the world. Studies have shown that vitamin D may play an important role in the development of obesity. The current study was conducted to quantitatively evaluate the association between serum 25-(OH) vitamin D levels and the risk of obesity in both diabetic and non-diabetic subjects. A systematic review and meta-analysis of observational studies was carried out for that purpose. We searched the Medline, PubMed, and Embase databases throughout all of March 2018. A total of fifty five observational studies for both diabetic and non-diabetic subjects were finally included in the meta-analysis. The data were analyzed by comprehensive meta-analysis software version 3 and the random effects model was used to analyze the data. The meta-analysis showed an overall inverse relationship between serum vitamin D status and body mass index (BMI) in studies of both diabetic (r = −0.173, 95% = −0.241 to −0.103, p = 0.000) and non-diabetic (r = −0.152, 95% = −0.187 to −0.116, p = 0.000) subjects. The evidence of publication bias was not found in this meta-analysis. In conclusion, the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects. Reliable evidence from well-designed future randomized controlled trials is required to confirm the findings from observational studies and to find out the potential regulatory effects of vitamin D supplementation to lower BMI.

scholarly journals Vitamin D status and risk of incident tuberculosis disease: a systematic review and individual participant data meta-analysis

2018 ◽  
Author(s):  
Omowunmi Aibana ◽  
Chuan-Chin Huang ◽  
Said Aboud ◽  
Alberto Arnedo-Pena ◽  
Mercedes C. Becerra ◽  
...  
Keyword(s):  
Vitamin D ◽  
Clinical Trials ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Dependent Manner ◽  
Individual Participant Data ◽  
Vitamin D Levels ◽  
Clinical Trials Unit ◽  
Individual Participant ◽  
The Impact

ABSTRACTBackgroundFew studies have evaluated the association between pre-existing vitamin D deficiency (VDD) and incident TB. We assessed the impact of baseline vitamin D on TB risk.MethodsWe assessed the association between baseline vitamin D and incident TB in a prospective cohort of 6751 household contacts of TB patients in Peru. We also conducted a one-stage individual participant data meta-analysis searching PubMed and Embase for studies of vitamin D and TB until December 31, 2017. We included studies that assessed vitamin D before TB diagnosis. We defined VDD as 25–(OH)D <50 nmol/L, insufficiency as 50–75 nmol/L and sufficiency as >75nmol/L. We estimated the association between vitamin D and incident TB using conditional logistic regression in the Peru cohort and generalized linear mixed models in the meta-analysis.FindingsIn Peru, baseline VDD was associated with a statistically insignificant increase in incident TB (aOR 1·70, 95% CI 0·84–3·46; p=0·14). We identified seven studies for the meta-analysis and analyzed 3544 participants. Individuals with VDD and very low vitamin D (<25nmol/L) had increased TB risk (aOR 1·48, 95% CI 1·04–210;p=0· 03 and aOR 2 08, 95% CI 0·88–4·92; p trend=002 respectively). Among HIV-positive patients, VDD and very low vitamin D conferred a 2-fold (aOR 2.18, 95% CI 1· 22–3·90; p=0· 01) and 4-fold (aOR 4·28, 95% CI 0·85–21·44; p trend=0·01) increased risk of TB respectively.InterpretationOur findings suggest vitamin D predicts TB risk in a dose-dependent manner and vitamin D supplementation may play a role in TB prevention.FundingNational Institute of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), National Institute on Drug Abuse (NIDA), National Institute of Mental Health (NIMH), International Maternal Pediatric Adolescent AIDS Clinical Trials Group (IMPAACT), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institute of Dental and Craniofacial Research (NIDCR), Boehringer-Ingelheim, Bristol-Myers Squibb, Gilead Sciences, GlaxoSmithKline, Foundation, Ujala Foundation, Wyncote Foundation, NIH - Fogarty International Center Program of International Training Grants in Epidemiology Related to AIDS, NIAID Byramjee Jeejeebhoy Medical College HIV Clinical Trials Unit, NIAID’s Baltimore-Washington-India Clinical Trials Unit, National Commission on Biotechnology, the Higher Education Commission, International Research Support Initiative Program of the Higher Education Commission Government of Pakistan, the Bill and Melinda Gates Foundation, and the NIH Fogarty International Center.Research in ContextEvidence before this studyNumerous studies have found lower serum vitamin D levels among patients with active TB disease compared to healthy controls. However, research has not clarified whether low vitamin D increases TB risk or whether TB disease leads to decreased vitamin D levels. We conducted PubMed and Medline searches for all studies available through December 31, 2017 on the association between vitamin D status and TB disease. We included the following keywords: “vitamin D,” “vitamin D deficiency,” “hypovitaminosis D,” “25-hydroxyvitamin D,” “1,25-dihydroxyvitamin D,” “vitamin D2,” “vitamin D3,” “ergocalciferol,” “cholecalciferol,” and “tuberculosis.” We found only seven studies had prospectively evaluated the impact of baseline vitamin D levels on risk of progression to TB disease.We report here the results of a case control study nested within a large prospective longitudinal cohort study of household contacts of TB cases and the results of an individual participant data (IPD) metaanalysis of available evidence on the association between vitamin D levels and incident TB disease.Added value of this studyWe demonstrated that low vitamin D levels predicts risk of future progression to TB disease in a dose-dependent manner.Implications of all the available evidenceThese findings suggest the possibility that vitamin D supplementation among individuals at high risk for developing TB disease might play a role in TB prevention efforts.

Vitamin D and Vascular Disease

2020 ◽  
Vol 19 (3) ◽  
pp. 250-268 ◽  
Author(s):  
Ioanna Gouni-Berthold ◽  
Heiner K. Berthold
Keyword(s):  
Risk Factors ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D Supplementation ◽  
Plasma Vitamin ◽  
Cvd Risk ◽  
Vitamin D Receptors ◽  
Cell Proliferation And Differentiation ◽  
Increased Risk ◽  
Vitamin D Levels

: 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.

The effect of vitamin D-related interventions on multiple sclerosis relapses: a meta-analysis

2013 ◽  
Vol 19 (12) ◽  
pp. 1571-1579 ◽  
Author(s):  
Eleanor James ◽  
Ruth Dobson ◽  
Jens Kuhle ◽  
David Baker ◽  
Gavin Giovannoni ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Vitamin D ◽  
Relative Risk ◽  
Controlled Trial ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
High Dose ◽  
Vitamin D Levels ◽  
High Dose Vitamin ◽  
Risk Of Relapse

Observational studies have shown an association between lower vitamin D levels and higher risk of relapse among people with multiple sclerosis (MS). This has raised interest in potential clinical benefits of vitamin D supplementation in the management of MS. The objectives were to examine the effect of vitamin D based interventions on the relative risk of relapse in MS. Any randomised controlled trial assessing the effect on the relative risk of relapse of any formulation or dose of vitamin D, in participants with MS, was eligible. The inverse variance with random effects model in Review Manager 5.1 was used to calculate the odds ratio of relapses in high dose vitamin D treated patients vs. controls. Five studies were published as of September 2012, yielding a total of 129 high-dose vitamin D-treated patients and 125 controls. We found no significant association between high-dose vitamin D treatment and risk of MS relapse (OR 0.98, 95% CI 0.45–2.16). In conclusion, although no significant association between high-dose vitamin D treatment and risk of MS relapses was found, the studies were limited by several methodological limitations. Further larger, more prolonged studies are merited.

scholarly journals Vitamin D and Periodontitis: A Systematic Review and Meta-Analysis

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2177 ◽  
Author(s):  
Vanessa Machado ◽  
Sofia Lobo ◽  
Luís Proença ◽  
José João Mendes ◽  
João Botelho
Keyword(s):  
Vitamin D ◽  
Chronic Periodontitis ◽  
Meta Analysis ◽  
Serum Levels ◽  
Aggressive Periodontitis ◽  
Vitamin D Supplementation ◽  
Cochrane Library ◽  
Healthy Controls ◽  
Hydroxyvitamin D ◽  
Vitamin D Levels

To explore the vitamin D levels of periodontitis patients in comparison with periodontally healthy ones, and to assess the influence of vitamin D supplementation as an adjunctive during nonsurgical periodontal treatment (NSPT). Five databases (Pubmed, Embase, Scholar, Web of Sciences, and Cochrane Library) were searched until May 2020. Mean difference (MD) meta-analysis with corresponding 95% confidence interval (95% CI) and sensitivity tests via meta-regression were used. We followed Strength of Recommendation Taxonomy (SORT) to appraise the strength and quality of the evidence. Sixteen articles were included, fourteen case-control and two intervention studies, all reporting 25-hydroxyvitamin D (25(OH)D) levels. Compared with the healthy controls, the circulating 25(OH)D levels were significantly lower in chronic periodontitis patients (pooled MD = −6.80, 95% CI: −10.59 to −3.02). Subgroup analysis revealed differences among 25(OH)D measurements, with liquid chromatography-mass spectrometry being the most homogeneous method (pooled MD = −2.05, 95% CI: −3.40 to −0.71). Salivary levels of 25(OH)D showed no differences between groups. Due to the low number of studies, conclusions on aggressive periodontitis and in the effect of vitamin D supplementation after NSPT were not possible to ascribe. Compared with healthy controls, 25(OH)D serum levels are significantly lower in chronic periodontitis patients, with an overall SORT A recommendation. Future studies are needed to clarify the effect of vitamin D supplementation and the biological mechanisms linking vitamin D to the periodontium.

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