Vitamin D and survival in COVID-19 patients: A quasi-experimental study.
Level 3 - non-randomized controlled study
Non-randomized controlled cohort study
PubMed 33065275 · doi:10.1016/j.jsbmb.2020.105771
What was done
A quasi-experimental study evaluated 66 frail elderly residents with COVID-19 at a French nursing home. Participants who received bolus vitamin D3 supplementation during COVID-19 or in the preceding month (intervention group, n = 57; mean age 87.7 ± 9.3 years) were compared with those who did not (comparator group, n = 9; mean age 87.4 ± 7.2 years). Primary and secondary outcomes were COVID-19 mortality and acute-phase Ordinal Scale for Clinical Improvement (OSCI) score over a mean follow-up of 36 ± 17 days. Analyses adjusted for age, sex, number of daily medications, functional abilities, albuminemia, use of corticosteroids, hydroxychloroquine, or antibiotics, and hospitalization.
What was found
Survival was 82.5% in the vitamin D3 intervention group compared to 44.4% in the comparator group (P = 0.023). In fully adjusted models, vitamin D3 supplementation was associated with a significant reduction in mortality (HR = 0.11, 95% CI: 0.03 to 0.48, P = 0.003) and longer survival time on Kaplan-Meier analysis (log-rank P = 0.002). Vitamin D3 supplementation was also inversely associated with the OSCI score for COVID-19 severity (β = -3.84, 95% CI: -6.07 to -1.62, P = 0.001).
Why it matters
This paper suggests that recent or acute bolus vitamin D3 supplementation is linked to markedly improved survival and reduced illness severity in frail elderly nursing-home residents infected with COVID-19.
Limits
The sample size was very small (n = 66) with a severe imbalance between groups (57 in the intervention group vs. 9 in the comparator), heightening the risk of statistical instability and unmeasured confounding. The study was observational and non-randomized, conducted in a single French nursing home, which limits generalizability. Baseline vitamin D levels and exact dosing regimens were not reported in the abstract.
Cited by
- supports A French study of nursing home residents hospitalized with COVID-19 found significantly better clinical outcomes in patients who had received an 80,000 IU vitamin D dose within the preceding 30 days compared to those who received it over 30 days prior.