Exploring the association between vitamin D status and Corona Virus-19 infection in a cohort of adults aged 50 years and older

Abstract

Objective

Evaluate the association between vitamin D (vitD) status and Corona Virus-19 (COVID-19) infection in adults aged 50 years and older.

Design

Adults ≥50 undergoing COVID-19 testing from July 2020 to December 2021, without prior vaccination, consented to blood analysis. SARS-CoV-2 PCR confirmed current COVID-19 infection. VitD status was assessed via 25(OH)D concentration (LCMS/MS, ZRT Labs, Portland, OR). Sociodemographic data were collected at enrollment. Statistical analyses (SAS 9.4) examined associations between sociodemographics, COVID-19, and vitD status. Multivariate logistic regression analyzed factors linked to COVID-19 or vitD status.

Results

Of 131 participants, 46.6% were ≥65 years old, 71.0% married, 19.9% Black American, 36.6% male, 38.9% Medicaid/Medicare/self-pay, and 42.8% BMI≥30. VitD status and Black American (P=0.0001) significantly associated with COVID-19 infection (P=0.0001). Black American (P=0.0003), males (P=0.003), and BMI (P=0.007) were inversely associated with 25(OH)D concentration. In a multiple logistic regression model predicting COVID-19 infection, only vitamin D status remained significant after controlling for certain sociodemographic and clinical factors (P<0.0001, OR 0.92, 95% CI 0.89–0.95).

Of the 44 COVID-positive participants, 35 (79.6%) were hospitalized and 19 (43.2%) were admitted to the Intensive Care Unit (ICU). Hospitalization due to COVID-19 was associated with age ≥65 years old (P=0.02; OR 12.0, 95% CI 1.34–106.79), male (P=0.02, OR 10.7, 95% CI 1.20–94.73), and 25(OH)D <40 ng/mL (P=0.0006, OR 42.5, 95% CI 3.90–461.01). In multivariate analysis, the association between vitamin D status and the risk of COVID-related hospitalization remained significant and inversely associated (P=0.03, OR 0.88, 95% CI 0.78–0.99).

In unadjusted analysis, COVID pneumonia was associated with male sex (P=0.049; OR 4.6, 95% CI 1.06–20.16) and 25(OH)D <40 ng/mL (P=0.006, OR 18.8, 95% CI 1.9–184.10). Participants with COVID infection and 25(OH)D <20 ng/mL were 2.1 times more likely to be admitted to ICU/death (P=0.03). In unadjusted analysis, ICU admission and/or death were linked to age ≥65 years (P=0.0002, OR 16.9, 95% CI 3.63–78.56), Medicaid/Medicare/self-pay insurance status (P=0.004, OR 0.1, 0.04–0.56), and 25(OH)D <20 (P=0.03, OR 3.9, 1.09–13.66) and <40 ng/mL (P=0.03); however, only age ≥65 remained significant in multivariate analysis (P=0.04, OR 6.7, CI 1.05–43.0).

Conclusions

Lower 25(OH)D concentration was a significant predictor and/or contributor to COVID-19 infection, suggesting the importance of maintaining adequate vitamin D status in reducing infection risk and mitigating severe outcomes.