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Meta-Analysis
. 2021 Mar:104:58-64.
doi: 10.1016/j.ijid.2020.12.077. Epub 2021 Jan 2.

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis

Nanyang Liu  1 , Jiahui Sun  2 , Xiyuan Wang  2 , Tingting Zhang  3 , Ming Zhao  2 , Hao Li  4
Affiliations
Meta-Analysis

Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis

Nanyang Liu et al. Int J Infect Dis. 2021 Mar.

Abstract

Background: Observational studies suggest that the risk and clinical prognosis of coronavirus disease 2019 (COVID-19) are related to low vitamin D status; however, the data are inconsistent.

Objectives: We conducted a systematic review and meta-analysis to assess the association between low vitamin D status and COVID-19.

Methods: A systematic search was conducted with PubMed, Embase, and the Cochrane Library from database inception to September 25, 2020. The standardized mean difference (SMD) or odds ratio (OR) and corresponding 95% confidence interval (CI) was applied to estimate pooled results. Random - or fixed-effect models based on heterogeneity were used for the meta-analysis. Funnel plots and Egger regression tests were used to assess publication bias.

Results: A total of ten articles with 361,934 participants were selected for meta-analysis. Overall, the pooled OR in the fixed-effect model showed that vitamin D deficiency or insufficiency was associated with an increased risk of COVID-19 (OR = 1.43, 95% CI 1.00-2.05). In addition, COVID-19-positive individuals had lower vitamin D levels than COVID-19-negative individuals (SMD = -0.37, 95% CI = -0.52 to -0.21). Significant heterogeneity existed in both endpoints. Funnel plots and Egger regression tests revealed significant publication bias.

Conclusions: This systematic review and meta-analysis indicated that low vitamin D status might be associated with an increased risk of COVID-19 infection. Further studies are needed to evaluate the impact of vitamin D supplementation on the clinical severity and prognosis in patients with COVID-19.

Systematic review registration: PROSPERO registration no: CRD42020216740.

Keywords: 25-hydroxyvitamin D; Coronavirus disease 2019; Low vitamin D status; Meta-analysis; Vitamin D.

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Conflict of interest statement

The authors have no relevant interests to declare.

Figures

Figure 1
Figure 1
Flow diagram of the literature search process.
Figure 2
Figure 2
Results from the random-effect model that compared the odds of low vitamin D status among individuals with COVID-19 positivity and negativity. COVID-19 = coronavirus disease 2019.
Figure 3
Figure 3
Results from the random-effect model that compared the serum 25(OH)D levels among individuals with COVID-19 positivity and negativity. 25(OH)D = 25-hydroxyvitamin D; COVID-19 = coronavirus disease 2019.
Figure 4
Figure 4
Sensitivity analysis was performed by excluding each study in turn.
Figure 5
Figure 5
Subgroup analysis based on the 25(OH)D measurement units (ng/mL and nmol/L) comparing the serum vitamin D levels among individuals with COVID-19 positivity and negativity. 25(OH)D = 25-hydroxyvitamin D; COVID-19 = coronavirus disease 2019.
Figure 6
Figure 6
The visual forest plots were performed to assess publication bias. (a) represents binary variable; (b) represents continuous variable.
See this image and copyright information in PMC

References

    1. Al Mheid I., Quyyumi A.A. Vitamin D and Cardiovascular Disease: Controversy Unresolved. J Am Coll Cardiol. 2017;70(1):89–100. - PubMed
    1. Avolio A., Avataneo V., Manca A. 25-Hydroxyvitamin D Concentrations Are Lower in Patients with Positive PCR for SARS-CoV-2. Nutrients. 2020;12:1359. - PMC - PubMed
    1. Baktash V., Hosack T., Patel N. Vitamin D status and outcomes for hospitalised older patients with COVID-19. Postgrad Med J. 2020 doi: 10.1136/postgradmedj-2020-138712. - DOI - PMC - PubMed
    1. Beveridge La, Struthers Ad, Khan F., Jorde R., Scragg R., Macdonald Hm. Effect of Vitamin D Supplementation on Blood Pressure: a Systematic Review and Meta-analysis Incorporating Individual Patient Data. JAMA Intern Med. 2015;175(5):745–754. - PMC - PubMed
    1. Bouillon R. Comparative analysis of nutritional guidelines for vitamin D. Nat Rev Endocrinol. 2017;13:466–479. - PubMed