scholarly journals In sickness and in health: pivotal role of vitamin D

2020 ◽  
Vol 30 (2) ◽  
pp. 202-214 ◽  
Author(s):  
Nora Nikolac Gabaj ◽  
Tomislav Pavicic ◽  
Alen Vrtaric ◽  
Lara Milevoj Kopcinovic ◽  
Davorka Herman Mahecic ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Supplementation ◽  
Main Role ◽  
Vitamin D Metabolites ◽  
Gold Standard Method ◽  
Liquid Chromatography Tandem Mass ◽  
First Results ◽  
Preanalytical Variability ◽  
Open Question

Within the last several years, frequency of vitamin D testing has multiplied substantially all over the world, since it has been shown to have an important role in many diseases and conditions. Even though liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been identified as “gold standard” method for vitamin D measurement, most laboratories still use immunochemistry methods. Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D2 and 25(OH)D3 in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams. Vitamin D is mostly measured in serum or plasma, but new studies are showing importance of measuring vitamin D in pleural effusions, breast milk, urine, synovial fluid and saliva. Besides the main role in calcium homeostasis and bone metabolism, many studies linked vitamin D deficiency with cancer, cardiovascular diseases, diabetes, fertility and many other conditions. However, even though initial observational studies indicated that supplementation with vitamin D might be beneficial in disease development and progression; first results of well-designed randomized controlled prospective studies did not find differences in frequency of cardiovascular events or invasive cancer between patients taking vitamin D supplementation compared to placebo. In the light of these recent findings, validity of excessive vitamin D testing remains an open question.

The role of vitamin D in metabolic and reproductive disturbances of polycystic ovary syndrome: A narrative mini-review

2020 ◽  
pp. 1-8
Author(s):  
Daniela Menichini ◽  
Gianpiero Forte ◽  
Beatrice Orrù ◽  
Giuseppe Gullo ◽  
Vittorio Unfer ◽  
...  
Keyword(s):  
Vitamin D ◽  
Polycystic Ovary Syndrome ◽  
Embryo Quality ◽  
Polycystic Ovary ◽  
Vitamin D Supplementation ◽  
Endometrial Receptivity ◽  
Metabolic Disturbances ◽  
Ovary Syndrome ◽  
Beneficial Role

Abstract. Vitamin D is a secosteroid hormone that plays a pivotal role in several metabolic and reproductive pathways in humans. Increasing evidence supports the role of vitamin D deficiency in metabolic disturbances and infertility in women with polycystic ovary syndrome (PCOS). Indeed, supplementation with vitamin D seems to have a beneficial role on insulin resistance and endometrial receptivity. On the other hand, exceedingly high levels of vitamin D appear to play a detrimental role on oocytes development and embryo quality. In the current review, we summarize the available evidence about the topic, aiming to suggest the best supplementation strategy in women with PCOS or, more generally, in those with metabolic disturbances and infertility. Based on the retrieved data, vitamin D seems to have a beneficial role on IR, insulin sensitivity and endometrial receptivity, but high levels and incorrect timing of administration seem to have a detrimental role on oocytes development and embryo quality. Therefore, we encourage a low dose supplementation (400–800 IU/day) particularly in vitamin D deficient women that present metabolic disturbances like PCOS. As far as the reproductive health, we advise vitamin D supplementation in selected populations, only during specific moments of the ovarian cycle, to support the luteal phase. However, ambiguities about dosage and timing of the supplementation still emerge from the clinical studies published to date and further studies are required.

scholarly journals Does vitamin D supplementation prevent SARS-CoV-2 infection in military personnel? Review of the evidence

2021 ◽  
pp. bmjmilitary-2020-001686
Author(s):  
Iain T Parsons ◽  
R M Gifford ◽  
M J Stacey ◽  
L E Lamb ◽  
M K O'Shea ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Supplementation ◽  
Vitamin D Status ◽  
Military Studies ◽  
Vitamin D Receptors ◽  
Area Of Interest ◽  
Military Populations ◽  
Tract Infections ◽  
Recruit Training

For most individuals residing in Northwestern Europe, maintaining replete vitamin D status throughout the year is unlikely without vitamin D supplementation and deficiency remains common. Military studies have investigated the association with vitamin D status, and subsequent supplementation, with the risk of stress fractures particularly during recruit training. The expression of nuclear vitamin D receptors and vitamin D metabolic enzymes in immune cells additionally provides a rationale for the potential role of vitamin D in maintaining immune homeostasis. One particular area of interest has been in the prevention of acute respiratory tract infections (ARTIs). The aims of this review were to consider the evidence of vitamin D supplementation in military populations in the prevention of ARTIs, including SARS-CoV-2 infection and consequent COVID-19 illness. The occupational/organisational importance of reducing transmission of SARS-CoV-2, especially where infected young adults may be asymptomatic, presymptomatic or paucisymptomatic, is also discussed.

scholarly journals Vitamin D Metabolites and Clinical Outcome in Hospitalized COVID-19 Patients

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2129
Author(s):  
Sieglinde Zelzer ◽  
Florian Prüller ◽  
Pero Curcic ◽  
Zdenka Sloup ◽  
Magdalena Holter ◽  
...  
Keyword(s):  
Vitamin D ◽  
Degradation Products ◽  
University Hospital ◽  
Vitamin D Metabolites ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Relevant Role ◽  
Metabolite Ratio ◽  
The University

(1) Background: Vitamin D, a well-established regulator of calcium and phosphate metabolism, also has immune-modulatory functions. An uncontrolled immune response and cytokine storm are tightly linked to fatal courses of COVID-19. The present retrospective study aimed to inves-tigate vitamin D status markers and vitamin D degradation products in a mixed cohort of 148 hospitalized COVID-19 patients with various clinical courses of COVID-19. (2) Methods: The serum concentrations of 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 25,26(OH)2D3 were determined by a validated liquid-chromatography tandem mass-spectrometry method in leftover serum samples from 148 COVID-19 patients that were admitted to the University Hospital of the Medical Uni-versity of Graz between April and November 2020. Anthropometric and clinical data, as well as outcomes were obtained from the laboratory and hospital information systems. (3) Results: From the 148 patients, 34 (23%) died within 30 days after admission. The frequency of fatal outcomes did not differ between males and females. Non-survivors were significantly older than survivors, had higher peak concentrations of IL-6 and CRP, and required mechanical ventilation more frequently. The serum concentrations of all vitamin D metabolites and the vitamin D metabolite ratio (VMR) did not differ significantly between survivors and non-survivors. Additionally, the need for res-piratory support was unrelated to the serum concentrations of 25(OH)D vitamin D and the two vitamin D catabolites, as well as the VMR. (4) Conclusion: The present results do not support a relevant role of vitamin D for the course and outcome of COVID-19.

scholarly journals Implications of Vitamin D Research in Chickens can Advance Human Nutrition and Perspectives for the Future

2021 ◽  
Author(s):  
Matthew F Warren ◽  
Kimberly A Livingston
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D Supplementation ◽  
The Body ◽  
Human Nutrition ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Related Research ◽  
Vitamin D Intake ◽  
Increased Risk

Abstract The risk of vitamin D insufficiency in humans is a global problem that requires improving ways to increase vitamin D intake. Supplements are a primary means for increasing vitamin D intake, but without a clear consensus on what constitutes vitamin D sufficiency, there is toxicity risk with taking supplements. Chickens have been used in many vitamin D-related research studies, especially studies involving vitamin D supplementation. Our state-of-the-art review evaluates vitamin D metabolism and how the different hydroxylated forms are synthesized. We provide an overview with how vitamin D is absorbed, transported, excreted, and what tissues in the body store vitamin D metabolites. We also discuss a number of studies involving vitamin D supplementation with broilers and laying hens. Vitamin D deficiency and toxicity are also described and how they can be caused. The vitamin D receptor (VDR) is important for vitamin D metabolism. However, there is much more that can be understood with VDR in chickens. Potential research aims involving vitamin D and chickens should explore VDR mechanisms which could lead to newer insights with VDR. Utilizing chickens in future research to help with elucidating vitamin D mechanisms has great potential to advance human nutrition. Finding ways to increase vitamin D intake will be necessary because the coronavirus 2019 disease (COVID-19) pandemic is leading to increased risk of vitamin D deficiency in many populations. Chickens can provide a dual purpose with addressing pandemic-caused vitamin D deficiency: 1) vitamin D supplementation gives chickens added value with possibly leading to vitamin D-enriched meat and egg products; and 2) chickens’ use in research provides data for translational research. Expanding vitamin D-related research in chickens to include more nutritional aims in vitamin D status has great implications with developing better strategies to improve human health.

scholarly journals Vitamin D supplementation, COVID-19 and disease severity: a meta-analysis

QJM ◽  
2021 ◽  
Author(s):  
K Shah ◽  
D Saxena ◽  
D Mavalankar
Keyword(s):  
Vitamin D ◽  
Randomized Controlled Trials ◽  
Usual Care ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Vitamin D Supplementation ◽  
Hospitalized Patients ◽  
Controlled Trials ◽  
Randomized Controlled

Abstract Objective: Current meta-analysis aims to understand the effect of oral supplementation of vitamin D on intensive care unit (ICU) requirement and mortality in hospitalized COVID-19 patients. Methods: Databases PubMed, preprint servers, and google scholar were searched from December 2019 to December 2020. Authors searched for the articles assessing role of vitamin D supplementation on COVID-19. Cochrane RevMan tool was used for quantitative assessment of the data, where heterogeneity was assessed using I2 and Q statistics and data was expressed using odds ratio with 95% confidence interval. Results: Final meta-analysis involved pooled data of 532 hospitalized patients (189 on vitamin D supplementation and 343 on usual care/placebo) of COVID-19 from three studies (Two randomized controlled trials, one retrospective case-control study). Statistically (p<0.0001) lower ICU requirement was observed in patients with vitamin D supplementation as compared to patients without supplementations (odds ratio: 0.36; 95% CI: 0.210-0.626). However, it suffered from significant heterogeneity, which reduced after sensitivity analysis. In case of mortality, vitamin D supplements has comparable findings with placebo treatment/usual care (odds ratio: 0.93; 95% CI: 0.413-2.113; p=0.87). The studies did not show any publication bias and had fair quality score. Subgroup analysis could not be performed due to limited number of studies and hence dose and duration dependent effect of vitamin D could not be evaluated. Conclusions: Although the current meta-analysis findings indicate potential role of vitamin D in improving COVID-19 severity in hospitalized patients, more robust data from randomized controlled trials are needed to substantiate its effects on mortality.

scholarly journals Vitamin D signalling in adipose tissue

2012 ◽  
Vol 108 (11) ◽  
pp. 1915-1923 ◽  
Author(s):  
Cherlyn Ding ◽  
Dan Gao ◽  
John Wilding ◽  
Paul Trayhurn ◽  
Chen Bing
Keyword(s):  
Vitamin D ◽  
Adipose Tissue ◽  
Vitamin D Deficiency ◽  
Vitamin D Metabolites ◽  
Hydroxyvitamin D ◽  
The Metabolic Syndrome ◽  
Prevalence Of Obesity ◽  
Adipose Tissue Development ◽  
And Function

Vitamin D deficiency and the rapid increase in the prevalence of obesity are both considered important public health issues. The classical role of vitamin D is in Ca homoeostasis and bone metabolism. Growing evidence suggests that the vitamin D system has a range of physiological functions, with vitamin D deficiency contributing to the pathogenesis of several major diseases, including obesity and the metabolic syndrome. Clinical studies have shown that obese individuals tend to have a low vitamin D status, which may link to the dysregulation of white adipose tissue. Recent studies suggest that adipose tissue may be a direct target of vitamin D. The expression of both the vitamin D receptor and 25-hydroxyvitamin D 1α-hydroxylase (CYP27B1) genes has been shown in murine and human adipocytes. There is evidence that vitamin D affects body fat mass by inhibiting adipogenic transcription factors and lipid accumulation during adipocyte differentiation. Some recent studies demonstrate that vitamin D metabolites also influence adipokine production and the inflammatory response in adipose tissue. Therefore, vitamin D deficiency may compromise the normal metabolic functioning of adipose tissue. Given the importance of the tissue in energy balance, lipid metabolism and inflammation in obesity, understanding the mechanisms of vitamin D action in adipocytes may have a significant impact on the maintenance of metabolic health. In the present review, we focus on the signalling role of vitamin D in adipocytes, particularly the potential mechanisms through which vitamin D may influence adipose tissue development and function.

scholarly journals Using genetic variants to evaluate the causal effect of serum vitamin D concentration on COVID-19 susceptibility, severity and hospitalization traits: a Mendelian randomization study

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhiyong Cui ◽  
Yun Tian
Keyword(s):  
Vitamin D ◽  
Fixed Effects ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Serum Vitamin ◽  
Vitamin D Supplementation ◽  
Sensitivity Analyses ◽  
Global Test ◽  
Serum Vitamin D

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has struck globally and is exerting a devastating toll on humans. The pandemic has led to calls for widespread vitamin D supplementation in public. However, evidence supporting the role of vitamin D in the COVID-19 pandemic remains controversial. Methods We performed a two-sample Mendelian randomization (MR) analysis to analyze the causal effect of the 25-hydroxyvitamin D [25(OH)D] concentration on COVID-19 susceptibility, severity and hospitalization traits by using summary-level GWAS data. The causal associations were estimated with inverse variance weighted (IVW) with fixed effects (IVW-fixed) and random effects (IVW-random), MR-Egger, weighted edian and MR Robust Adjusted Profile Score (MR.RAPS) methods. We further applied the MR Steiger filtering method, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) global test and PhenoScanner tool to check and remove single nucleotide polymorphisms (SNPs) that were horizontally pleiotropic. Results We found no evidence to support the causal associations between the serum 25(OH)D concentration and the risk of COVID-19 susceptibility [IVW-fixed: odds ratio (OR) = 0.9049, 95% confidence interval (CI) 0.8197–0.9988, p = 0.0473], severity (IVW-fixed: OR = 1.0298, 95% CI 0.7699–1.3775, p = 0.8432) and hospitalized traits (IVW-fixed: OR = 1.0713, 95% CI 0.8819–1.3013, p = 0.4878) using outlier removed sets at a Bonferroni-corrected p threshold of 0.0167. Sensitivity analyses did not reveal any sign of horizontal pleiotropy. Conclusions Our MR analysis provided precise evidence that genetically lowered serum 25(OH)D concentrations were not causally associated with COVID-19 susceptibility, severity or hospitalized traits. Our study did not provide evidence assessing the role of vitamin D supplementation during the COVID-19 pandemic. High-quality randomized controlled trials are necessary to explore and define the role of vitamin D supplementation in the prevention and treatment of COVID-19.

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