Seasonal variation of vitamin D among healthy adult men in a subtropical region

Fontanive, Tiago Oselame; Dick, Nídea Rita Michels; Valente, Mariana Costa Silva; Laranjeira, Vani dos Santos; Antunes, Marina Venzon; Corrêa, Marcelo de Paula; Alves, Rita de Cássia Marques; Linden, Rafael; Furlanetto, Tânia Weber

doi:10.1590/1806-9282.66.10.1431

Cited by 7 publications

(4 citation statements)

References 20 publications

(1 reference statement)

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“…Optimal conditions for vitamin D biosynthesis may differ in each individual, and seasonal changes in sunlight exposure may also have an impact ( 6 – 9 ). Notably, previous research has also shown that vitamin D levels can drastically decrease from summer to winter in adult and young (apparently) healthy subjects of different ethnicities ( 10 – 15 ).…”

Section: Introductionmentioning

confidence: 92%

Can vitamin D status influence seroconversion to SARS-COV2 vaccines?

et al. 2022

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Existing data indicate an association between vitamin D deficiency and increased severity of respiratory distress due to COVID-19 infection, especially in high-risk populations. To date, the effect of vitamin D on immunogenicity to SARS-CoV-2 vaccines has been investigated solely in young healthcare workers in a few studies, yielding conflicting findings, yet highlighting that the response to immunization is inversely related to age. Vitamin D status can potentially influence the antibody titers in people with a previous (or naïve) SARS-CoV-2 infection and vaccination, given its role in immune regulatory functions. From this standpoint, vitamin D supplementation can help reduce the risk of SARS-CoV-2 infection, COVID-19 severity/mortality and rebalance immunological function, particularly in subjects with vigorous T lymphocyte responses to COVID-19. However, more research is needed to establish a correlation between vitamin D status and the generation of protective serological responses to SARS-CoV-2 vaccination.

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Section: Introductionmentioning

confidence: 92%

Can vitamin D status influence seroconversion to SARS-COV2 vaccines?

et al. 2022

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“…Vitamin D has known biological variability, and its serum levels can vary from 13%-26% over 4 months. The levels can also vary with age and with the emergence of comorbidities (46)(47)(48)(49)(50).…”

Section: Discussionmentioning

confidence: 99%

Is the vitamin D status of patients with COVID-19 associated with reduced mortality? A systematic review and meta-analysis

Bignardi¹,

Castello²,

Aquino³

et al. 2023

Archives of Endocrinology and Metabolism

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To conduct a systematic review and meta-analysis of studies assessing the association between serum vitamin D status and mortality in patients with COVID-19. We searched PubMed and Embase for studies addressing the association of serum vitamin D levels and COVID-19 mortality published until April 24, 2022. Risk ratios (RRs) and 95% confidence interval (CIs) were pooled using fixed or random effects models. The risk of bias was assessed using the Newcastle-Ottawa Scale. The meta-analysis included 21 studies that measured serum vitamin D levels close to the date of admission, of which 2 were casecontrol and 19 were cohort studies. Vitamin D deficiency was associated with COVID-19 mortality in the overall analysis but not when the analysis was adjusted to vitamin D cutoff levels < 10 or < 12 ng/mL (RR 1.60, 95% CI 0.93-2.27, I 2 60.2%). Similarly, analyses including only studies that adjusted measures of effect for confounders showed no association between vitamin D status and death. However, when the analysis included studies without adjustments for confounding factors, the RR was 1.51 (95% CI 1.28-1.74, I 2 0.0%), suggesting that confounders may have led to many observational studies incorrectly estimating the association between vitamin D status and mortality in patients with COVID-19. Deficient vitamin D levels were not associated with increased mortality rate in patients with COVID-19 when the analysis included studies with adjustments for confounders. Randomized clinical trials are needed to assess this association.

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“…The biological variability of vitamin D is known, and its plasma levels can vary from 13 to 26% in 4 months. Plasma vitamin D can also vary with age and the appearance of comorbidities [36][37][38][39][40].…”

Section: Discussionmentioning

confidence: 99%

Is the vitamin D status of patients with COVID-19 associated with reduced mortality?

Bignardi¹,

P²,

B³

et al. 2021

Preprint

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A systematic review with meta–analysis was performed to assess a possible association between plasma vitamin D levels and mortality in patients with COVID–19. PubMed, EMBASE, and Cochrane Library databases were searched. Studies involving COVID-19 patients that reported an association between plasma vitamin D levels and COVID–19 mortality published until February 5, 2020, were included. The risk ratio (RR) and confidence interval (CI) were pooled using a fixed–effects or random-effects model. A total of 11 studies that measured plasma vitamin D levels at admission were included in the meta–analysis, ten cohorts and one case-controls. Low plasma vitamin D levels (25(OH)D) in patients with COVID-19 were not associated with mortality (RR=1.35, 95%CI 0.84–1.86). Subgroup analysis by vitamin D cut–off (<20 or 25 ng/ml and <10 or 12 ng/ml) showed were not associated with mortality. When the RR in mortality analysis was calculated included four studies that did not perform adjusted analysis for confounding factors, the result was 1.43 (95% CI 1.18–1.69), suggesting that confounders may have led many observational studies to incorrectly estimate the association between vitamin D status and mortality in COVID–19 patients. Deficient vitamin D levels were not associated with a higher mortality rate in patients with COVID–19. Randomized clinical trials are needed to assess this association.

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Seasonal variation of vitamin D among healthy adult men in a subtropical region

Cited by 7 publications

References 20 publications

Can vitamin D status influence seroconversion to SARS-COV2 vaccines?

Can vitamin D status influence seroconversion to SARS-COV2 vaccines?

Is the vitamin D status of patients with COVID-19 associated with reduced mortality? A systematic review and meta-analysis

Is the vitamin D status of patients with COVID-19 associated with reduced mortality?

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