Impact of low vitamin d levels on COVID-19-related hospitalization and mortality: Results from a national cohort of veterans affairs patients

Objective: This study investigated whether low vitamin D levels are independently associated with COVID-19-related hospitalization and mortality Methods: A retrospective cohort of 5,634 COVID-19+ patients with recent Vitamin D labs receiving care at US Department of Veteran Affairs (VA) health care facilities from February 20, 2020 to November 8, 2020, was identified Vitamin D level was ascertained using the 25-hydroxyvitamin D3 or D2+D3 test result within 90 days preceding the index positive COVID-19 test Study outcomes were: (1) inpatient hospitalization requiring isolation and (2) 30-day mortality among those hospitalized Poisson Generalized Linear Models with robust errors and adjusted for sociodemographics and comorbidities were used to estimate outcome probabilities conditional on the log of Vitamin D levels Results: Of 5,634 veterans with a positive COVID-19 test, 707 (12 6%) were female, mean age was 62 5 (SD +/-15 1);1,920 (34 1%) identified as non-White, and 623 (11 1%) as Latinx Low vitamin D levels (<20 ng/ml) were found in 794 (14 1%) and 1,162 (20 6%) were hospitalized for COVID-19 infection After adjusting for all covariates, the probability of hospitalization was 23 7% for those with Vitamin D levels of 15ng/ml, but decreased to 19 8% for patients with higher vitamin D levels of 40 ng/ml, [Adjusted Relative Risk (ARR)=1 20 (1 06, 1 36, p= 004)] Among 1,162 hospitalized patients, 186 (16 0%) died within 30 days The adjusted mortality rate for patients with Vitamin D levels of 15 ng/ml was 22 3% and decreased to 14 4% for patients with higher vitamin D levels of 40 ng/ml, [ARR=1 55 (1 11,2 18, p= 011)] Conclusion: Vitamin D level may have a role in predicting COVID-19-related hospitalization and mortality;larger trials are needed to determine if vitamin D supplementation improves COVID-19-related clinical outcomes