Examination of the Moderating Effect of Race on the Relationship between Vitamin D Status and COVID-19 Test Positivity Using Propensity Score Methods.

Crandell, Ian; Rockwell, Michelle; Whitehead, Phyllis; Carter, Kimberly Ferren; Hanlon, Alexandra

INTRODUCTION With a well-established role in inflammation and immune function, vitamin D status has emerged as a potential factor for coronavirus disease-2019 (COVID-19). OBJECTIVE The purpose of this study was to evaluate the moderating effect of race on the relationship between vitamin D status and the risk of COVID-19 test positivity, and to compare propensity score (PS) model results to those obtained from classical bivariate and multivariable models, which have primarily comprised the literature to date. METHODS Electronic health record (EHR) data from TriNetX (unmatched n = 21,629; matched n = 16,602) were used to investigate the effect of vitamin D status, as measured by 25-hydroxyvitamin D [25(OH)D], on the odds of experiencing a positive COVID-19 test using multivariable logistic regression models with and without PS methodology. RESULTS Having normal (≥ 30 ng/mL) versus inadequate 25(OH)D (< 30 ng/mL) was not associated with COVID-19 positivity overall (OR = 0.913, p = 0.18), in White individuals (OR = 0.920, p = 0.31), or in Black individuals (OR = 1.006, p = 0.96). When 25(OH)D was analyzed on a continuum, a 10 ng/mL increase in 25(OH)D lowered the odds of having a positive COVID-19 test overall (OR = 0.949, p = 0.003) and among White (OR = 0.935, p = 0.003), but not Black individuals (OR = 0.994, p = 0.75). CONCLUSIONS Models which use weighting and matching methods resulted in smaller estimated effect sizes than models which do not use weighting or matching. These findings suggest a minimal protective effect of vitamin D status on COVID-19 test positivity in White individuals and no protective effect in Black individuals.