scholarly journals Vitamin D and respiratory infection in adults

2011 ◽  
Vol 71 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Ilkka Laaksi
Keyword(s):  
Vitamin D ◽  
Vitamin D Insufficiency ◽  
Vitamin D Supplementation ◽  
Uvb Radiation ◽  
Promoter Regions ◽  
Vitamin D Receptors ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Tract Infections

Vitamin D insufficiency is a global issue that has significant implications for health. The classical role of vitamin D in bone mineralisation is well known; vitamin D deficiency leads to rickets, osteomalacia or osteoporosis. The role of vitamin D in an immune system is less known. Vitamin D is not an actual vitamin but a secosteroid hormone produced in the skin from 7-dehydrocholesterol after exposure to sunlight UVB radiation. Nutrition and supplements are main sources of vitamin D in wintertime in northern countries as sunlight exposure is inadequate for the production. For activation vitamin D needs to be hydroxylated in liver to form 25-hydroxyvitamin D and in kidney to 1,25-dihydroxyvitamin D, the most active hormone in Ca absorption in the gut. For determination of vitamin D status serum 25-hydroxyvitamin D level, the major circulating form of the hormone is to be measured. Vitamin D regulates gene expression through binding with vitamin D receptors, which dimerises with retinoid X receptor. This complex binds to vitamin D-responsive elements inside the promoter regions of vitamin D-responsive genes. Vitamin D has a key role in innate immunity activation; the production of antimicrobial peptides (cathelicidin and defensins) following Toll-like receptor stimulation by pathogen lipopeptides is dependent on sufficient level of 25-hydroxyvitamin D. Clinically, there is evidence of the association of vitamin D insufficiency and respiratory tract infections. There is also some evidence of the prevention of infections by vitamin D supplementation. Randomised controlled trials are warranted to explore this preventive effect.

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 The Benefits of Vitamin D Supplementation for Athletes: Better Performance and Reduced Risk of COVID-19

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3741
Author(s):  
William B. Grant ◽  
Henry Lahore ◽  
Michelle S. Rockwell
Keyword(s):  
Vitamin D ◽  
Vascular System ◽  
The United States ◽  
Vitamin D Supplementation ◽  
Sporting Events ◽  
Sports Teams ◽  
Hydroxyvitamin D ◽  
Personal Consequences ◽  
25 Hydroxyvitamin D ◽  
Tract Infections

The COVID-19 pandemic is having major economic and personal consequences for collegiate and professional sports. Sporting events have been canceled or postponed, and even when baseball and basketball seasons resumed in the United States recently, no fans were in attendance. As play resumed, several players developed COVID-19, disrupting some of the schedules. A hypothesis now under scientific consideration is that taking vitamin supplements to raise serum 25-hydroxyvitamin D [25(OH)D] concentrations could quickly reduce the risk and/or severity of COVID-19. Several mechanisms have been identified through which vitamin D could reduce the risks of infection and severity, death, and long-haul effects of COVID-19: (1) inducing production of cathelicidin and defensins to reduce the survival and replication of the SARS-CoV-2 virus; (2) reducing inflammation and the production of proinflammatory cytokines and risk of the “cytokine storm” that damages the epithelial layer of the lungs, heart, vascular system, and other organs; and (3) increasing production of angiotensin-converting enzyme 2, thus limiting the amount of angiotensin II available to the virus to cause damage. Clinical trials have confirmed that vitamin D supplementation reduces risk of acute respiratory tract infections, and approximately 30 observational studies have shown that incidence, severity, and death from COVID-19 are inversely correlated with serum 25(OH)D concentrations. Vitamin D supplementation is already familiar to many athletes and sports teams because it improves athletic performance and increases playing longevity. Thus, athletes should consider vitamin D supplementation to serve as an additional means by which to reduce risk of COVID-19 and its consequences.

scholarly journals Prediction of Bone Mass Density Variation by Bone Remodeling Markers in Postmenopausal Women with Vitamin D Insufficiency Treated with Calcium and Vitamin D Supplementation

2003 ◽  
Vol 88 (11) ◽  
pp. 5175-5179 ◽  
Author(s):  
Franck Grados ◽  
Michel Brazier ◽  
Saïd Kamel ◽  
Marc Mathieu ◽  
Nathalie Hurtebize ◽  
...  
Keyword(s):  
Vitamin D ◽  
Bone Remodeling ◽  
Elderly Women ◽  
Vitamin D Insufficiency ◽  
Vitamin D Supplementation ◽  
Hydroxyvitamin D ◽  
Bone Remodeling Markers ◽  
25 Hydroxyvitamin D ◽  
Total Body

Abstract The aim of this study was to determine whether early changes in bone markers could predict long-term response in bone mineral density (BMD) after calcium (500 mg) and vitamin D (400 IU) supplementation twice daily in ambulatory elderly women with vitamin D insufficiency (25-hydroxyvitamin D, <12 ng/ml). One hundred and ninety-two women (mean age, 75 ± 7 yr) were randomized to receive either the supplementation (n = 95) or a placebo (n = 97) in a double-blind, controlled clinical trial for 1 yr. In comparison with the placebo group, supplementation significantly increased BMD, normalized 25-hydroxyvitamin D and significantly decreased intact PTH and bone remodeling markers. The initial values of telopeptide cross-links were correlated with improvement in total body BMD [urinary N-telopeptides (NTX), r = 0.38; C-telopeptides (CTX), r = 0.32; serum CTX, r = 0.28], and the 3-month changes in the same markers were correlated with improvement in total body (urinary N-telopeptides, r = −0.29; serum CTX, r = −0.26) and vertebral BMD (CTX, r = −0.26; all P < 0.05). We concluded that short-term changes in bone resorption markers can predict long-term variations in BMD in elderly women with vitamin D insufficiency receiving calcium and vitamin D supplementation.

Vitamin D Supplementation and Physical Performance in Adolescent Swimmers

2015 ◽  
Vol 25 (4) ◽  
pp. 317-325 ◽  
Author(s):  
Gal Dubnov-Raz ◽  
Netachen Livne ◽  
Raanan Raz ◽  
Avner H. Cohen ◽  
Naama W. Constantini
Keyword(s):  
Vitamin D ◽  
Physical Performance ◽  
Swimming Performance ◽  
Vitamin D Insufficiency ◽  
Sport Performance ◽  
Vitamin D Supplementation ◽  
Performance Variables ◽  
Hydroxyvitamin D ◽  
Before And After ◽  
25 Hydroxyvitamin D

It is hypothesized that vitamin D insufficiency in athletes might negatively affect sport performance. The objective of this study was to examine the effect of vitamin D3 supplementation on physical performance of adolescent swimmers with vitamin D insufficiency. Fifty-three adolescent competitive swimmers with vitamin D insufficiency (serum 25-hydroxyvitamin-D concentrations (25(OH)D)<30ng/ml, mean 24.2 ± 4.8ng/ml) were randomized to receive 2,000IU/day of vitamin D3 or placebo for 12 weeks. Swimming performance at several speeds, arm-grip strength, and one-legged balance, were measured before and after supplementation. The age-adjusted changes in performance variables during the study were compared between groups. 25(OH) D concentrations at study end were significantly higher in the vitamin group compared with the placebo group (29.6 ± 6.5ng/ml vs. 20.3 ± 4.2ng/ml, p < .001), yet only 48% of the vitamin group became vitamin D sufficient with this dosing. No between-group differences were found in the changes of the performance variables tested. No significant differences in performance were found between participants that became vitamin D sufficient, and those who did not. No significant correlation was found between the change in serum 25(OH)D and ageadjusted balance, strength or swimming performance at study end. Vitamin D3 supplementation that raised serum 25(OH)D concentrations by a mean of 9.3ng/ml above placebo in adolescent swimmers with vitamin D insufficiency, did not improve physical performance more than placebo.

scholarly journals A 250 μg/week dose of vitamin D was as effective as a 50 μg/d dose in healthy adults, but a regimen of four weekly followed by monthly doses of 1250 μg raised the risk of hypercalciuria

2013 ◽  
Vol 110 (10) ◽  
pp. 1866-1872 ◽  
Author(s):  
Sara R. Zwart ◽  
Howard Parsons ◽  
Michael Kimlin ◽  
Sheila M. Innis ◽  
James P. Locke ◽  
...  
Keyword(s):  
Vitamin D ◽  
Side Effects ◽  
Vitamin D Insufficiency ◽  
Vitamin D Supplementation ◽  
Healthy Adults ◽  
Dietary Vitamin ◽  
Steady Increase ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Dietary Vitamin D

The risk of vitamin D insufficiency is increased in persons having limited sunlight exposure and dietary vitamin D. Supplementation compliance might be improved with larger doses taken less often, but this may increase the potential for side effects. The objective of the present study was to determine whether a weekly or weekly/monthly regimen of vitamin D supplementation is as effective as daily supplementation without increasing the risk of side effects. Participants were forty-eight healthy adults who were randomly assigned for 3 months to placebo or one of three supplementation regimens: 50 μg/d (2000 IU/d, analysed dose 70 μg/d), 250 μg/week (10 000 IU/week, analysed dose 331 μg/week) or 1250 μg/week (50 000 IU/week, analysed dose 1544 μg/week) for 4 weeks and then 1250 μg/month for 2 months. Daily and weekly doses were equally effective at increasing serum 25-hydroxyvitamin D, which was significantly greater than baseline in all the supplemented groups after 30 d of treatment. Subjects in the 1250 μg treatment group, who had a BMI >26 kg/m2, had a steady increase in urinary Ca in the first 3 weeks of supplementation, and, overall, the relative risk of hypercalciuria was higher in the 1250 μg group than in the placebo group (P= 0·01). Although vitamin D supplementation remains a controversial issue, these data document that supplementing with ≤ 250 μg/week ( ≤ 10 000 IU/week) can improve or maintain vitamin D status in healthy populations without the risk of hypercalciuria, but 24 h urinary Ca excretion should be evaluated in healthy persons receiving vitamin D3 supplementation in weekly single doses of 1250 μg (50 000 IU).

scholarly journals Significant Independent Predictors of Vitamin D Deficiency in Inpatients and Outpatients of a Nephrology Unit

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Recep Bentli ◽  
Hulya Taskapan ◽  
Halil Toktaş ◽  
Ozkan Ulutas ◽  
Adnan Ozkahraman ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Female Gender ◽  
Vitamin D Insufficiency ◽  
Vitamin D Supplementation ◽  
Documentary Evidence ◽  
Hydroxyvitamin D ◽  
Nitrogen Levels ◽  
25 Hydroxyvitamin D ◽  
Higher Doses

Aims. Kidney disease was found to be a major risk factor for vitamin D deficiency in a population study of patients hospitalized. The aims of the study were to describe the prevalence of vitamin D deficiency inpatients and outpatients in a nephrology department during fall and to evaluate effect of assessing serum 25-hydroxyvitamin D (25(OH)D) levels and previous supplementation of cholecalciferol on vitamin D status.Methods. We studied 280 subjects in total, between October and January. The subjects were recruited from the following two groups: (a) inpatients and (b) outpatients in nephrology unit. We examined previous documentary evidence of vitamin D supplementation of the patients.Results. The prevalence of vitamin D deficiency among these 280 patients was 62,1% (174 patients). Fifty-three patients (18.9%) had severe vitamin D deficiency, 121 patients (43.2%) moderate vitamin D deficiency, and 66 patients (23.6%) vitamin D insufficiency. In logistic regression analysis female gender, not having vitamin D supplementation history, low serum albumin, and low blood urea nitrogen levels were significant independent predictors of vitamin D deficiency while no association of vitamin D deficiency with diabetes mellitus, serum creatinine, eGFR, and being hospitalized was found.Conclusion. Vitamin D deficiency, seems to be an important problem in both inpatients and outpatients of nephrology. Monitoring serum 25(OH)D concentrations regularly and replacement of vitamin D are important. Women in Turkey are at more risk of deficiency and may therefore need to consume higher doses of vitamin D.

scholarly journals Does the High Prevalence of Vitamin D Deficiency in African Americans Contribute to Health Disparities?

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 499
Author(s):  
Bruce N. Ames ◽  
William B. Grant ◽  
Walter C. Willett
Keyword(s):  
Vitamin D ◽  
African Americans ◽  
Vitamin D Deficiency ◽  
High Latitudes ◽  
Uvb Radiation ◽  
Vitamin D Status ◽  
Dark Skin ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Tract Infections

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer’s disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D3 supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.

scholarly journals Role of Vitamin D in Preeclampsia

2021 ◽  
Author(s):  
Simmi Kharb
Keyword(s):  
Vitamin D ◽  
Immune Dysfunction ◽  
Vitamin D Supplementation ◽  
Vitamin D Status ◽  
Infant Outcomes ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Vitamin D Signaling ◽  
Maternal And Infant Outcomes

Pathogenesis of preeclampsia involves immune dysfunction, placental implantation, abnormal angiogenesis, excessive inflammation, hypertension that may be affected by vitamin D. Human placenta expresses all the components for vitamin D signaling: Vitamin D receptor (VDR), retinoid X receptor (RXR), 1-alpha- hydroxylase (CYP27B1) and 24- hydroxylase (CYP24A1). Vitamin D binding protein plays a role in binding and transportation of 25 hydroxyvitamin D [25(OH)D] and 1,25(OH)2D3. Vitamin D is activated by 25-hydroxylase (CYP2R1) and 1-alpha -hydroxylase (CYP27B1) and is degraded by 24-hydroxylase (CYP24A1). Vitamin D supplementation is not recommended by WHO for pregnant women and allows recommended nutrient intake (RNI) of 200 IU (5 μg) per day. Further research requires serum 25(OH)D analysis and assessment of maternal and infant outcomes; pre-conceptional vitamin D status.

scholarly journals Vitamin D Supplementation in Sarcoidosis: A Double-Edged Sword

2021 ◽  
Author(s):  
Rishikesh Chandran ◽  
Lakshmi Nagendra ◽  
Shrikrishna Acharya ◽  
Giridhar Belur Hosmane ◽  
Vijith Shetty ◽  
...  
Keyword(s):  
Vitamin D ◽  
Disease Activity ◽  
Bone Health ◽  
Calcium Metabolism ◽  
Vitamin D Supplementation ◽  
Osteoporosis Prevention ◽  
Hydroxyvitamin D ◽  
Severe Hypercalcemia ◽  
25 Hydroxyvitamin D

AbstractSarcoidosis is complicated by disordered vitamin D and calcium metabolism, which has important implications on disease activity and bone health. Although the majority of the patients with sarcoidosis are typically deficient in 25-hydroxyvitamin D, repletion of vitamin D is controversial in light of the hypercalcemia risk. Presently, there are no clear guidelines regarding vitamin D supplementation as a part of osteoporosis prevention in patients with vitamin D deficiency and sarcoidosis. We report a patient with sarcoidosis who presented with severe hypercalcemia following vitamin D supplementation and review the debated role of vitamin D supplementation in vitamin D-deficient sarcoid patients.

scholarly journals Vitamin D levels and risk of COVID-19 infection: A systematic review

2021 ◽  
Vol 19 (2) ◽  
pp. 83-90
Author(s):  
Ana C. Coelho-Oliveira ◽  
Bruno B. Monteiro-Oliveira ◽  
Rebeca B. M. Cavalcante ◽  
Daniel B. Santos ◽  
Anelise Sonza ◽  
...  
Keyword(s):  
Systematic Review ◽  
Vitamin D ◽  
Randomized Clinical Trials ◽  
Vitamin D Supplementation ◽  
Eligibility Criteria ◽  
Hydroxyvitamin D ◽  
Vitamin D Levels ◽  
25 Hydroxyvitamin D ◽  
Novel Coronavirus ◽  
Tract Infections

Objective: Consistent independent associations between lowserum 25-hydroxyvitamin D concentrations and susceptibilityto acute respiratory tract infections have suggested apossible involvement of vitamin D in reducing the risk ofrespiratory infections and proposing its replacement as apotential strategy for prevention or treatment in this context.However, the role of vitamin D supplementation in theinfection by the novel coronavirus named SARS-CoV-2 isstill under investigation and no clinical evidence has beenreported to date. Methods: Electronic searches in Pubmed,Embase and Scopus databases were conducted and threecohort studies that analyzed the effects of interaction ofvitamin D with COVID-19, published only in English, wereincluded. Two reviewers, which independently examinedtitles and abstracts, identified records through database searchand reference screening and irrelevant studies were excludedbased in eligibility criteria. Relevant full texts were analyzedfor eligibility, and all relevant studies were included in thesystematic review. Results: Three cohort studies were includedin this systematic review with a mean methodologicalquality low. Only one study demonstrated interaction of lowvitamin D concentration in patients with a positive diagnosisfor COVID-19. Randomized clinical trials and studies of goodmethodological quality are necessary to confirm the findingsof this systematic review. Conclusions: This systematic reviewhas not demonstrated consistent associations between lowlevels of vitamin D and susceptibility to COVID-19 infection.Further studies on vitamin D supplementation for the preventionof COVID-19 infection should be conducted..

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