Healthcare Costs and Healthcare Utilization Outcomes of Vitamin D3 Supplementation at 5000 IU Daily during a 10.9 Month Observation Period within a Pragmatic Randomized Clinical Trial

Vitamin D insufficiency has been linked to multiple conditions including bone disease, respiratory disease, cardiovascular disease, diabetes, and cancer. Observational studies indicate lower healthcare costs and healthcare utilization with sufficient vitamin D levels. The secondary aims of our previously published pragmatic clinical trial of vitamin D3 supplementation were comparisons of healthcare costs and healthcare utilization. Comparisons were made between the vitamin D3 at 5000 IU supplementation group and a non-supplemented control group. Costs of care between the groups differed but were not statistically significant. Vitamin D3 supplementation reduced healthcare utilization in four major categories: hospitalizations for any reason (rate difference: −0.19 per 1000 person-days, 95%-CI: −0.21 to −0.17 per 1000 person-days, p < 0.0001); ICU admissions for any reason (rate difference: −0.06 per 1000 person-days, 95%-CI: −0.08 to −0.04 per 1000 person-days, p < 0.0001); emergency room visits for any reason (rate difference: −0.26 per 1000 person-days, 95%-CI: −0.46 to −0.05 per 1000 person-days, p = 0.0131; and hospitalizations due to COVID-19 (rate difference: −8.47 × 10⁻³ per 1000 person-days, 95%-CI: −0.02 to −1.05 × 10⁻³ per 1000 person-days, p = 0.0253). Appropriately powered studies of longer duration are recommended for replication of these utilization findings and analysis of cost differences.