Correlation between Serum Vitamin D3 Levels and Severity of COVID-19, Experience from a COVID-19-Dedicated Tertiary Care Hospital from Western India

Indian J Endocrinol Metab. 2023 Mar-Apr;27(2):170-176. doi: 10.4103/ijem.ijem_383_22. Epub 2023 Apr 14.

Abstract

Context: It is postulated that 25(OH)D deficiency is associated with a worse prognosis of COVID-19.

Aims: We aimed to find out whether baseline serum 25-hydroxy vitamin D levels were correlated with COVID-19 disease severity or not in Indian population.

Settings and design: It is a prospective observational study.

Methods and material: We prospectively recruited 200 COVID-19-positive adult patients and measured their baseline vitamin D levels on admission and prospectively followed their clinical course for their outcome and correlated the association.

Statistical analysis used: The continuous data were represented as mean (±SD) or median (IQR), while the categorical data were represented as proportions. Parametric data were analysed using unpaired T-test and ANOVA for two and more than two groups, and for categorical, nonparametric data, Chi-square test were applied. A two-sided P value of <0.05 was considered as statistically significant with 95% confidence interval.

Results: Eighty-six per cent (172/200) of patients had hypovitaminosis D (<30 ng/mL). The prevalence of 25(OH) severe deficiency, deficiency and vitamin D insufficiency was 23%, 41% and 22%, respectively. Clinical severity was graded as asymptomatic (11%), mild (14%), moderate (14.5%), severe (37.5%) and critical (22%). Sixty per cent of patients had clinically severe or critical disease requiring oxygen support with eleven per cent (n = 22) mortality overall. Age (P: 0.001), HTN (P: 0.049) and DM (P: 0.018) were negatively associated with clinical severity. No linear association was found between vitamin D levels and clinical severity. Low vitamin D levels had a significant inverse association with inflammatory markers like neutrophil-lymphocyte ratio (NLR, P: 0.012) and IL-6 (P: 0.002).

Conclusions: Vitamin D deficiency was not associated with worse outcomes of COVID-19 infection in Indian population.

Keywords: COVID-19; inflammation; neutrophil–lymphocyte ratio; vitamin D deficiency.