Review the Research
Get summaries of key research on vitamin D and COVID-19
Vitamin D Supplementation Associated to Better Survival in Hospitalized Frail Elderly COVID-19 Patients: The GERIA-COVID Quasi-Experimental Study.
Take Home Message
Large oral doses of vitamin D taken in the year prior to COVID-19 diagnosis were associated with less severe disease and better survival in frail elderly patients in France. Supplementation with 80,000 IU vitamin D3 after the diagnosis of COVID-19 was not associated with improved patient outcomes.
Results
- Seventeen participants experienced severe COVID-19, and 62 participants survived COVID-19 at day 14, while 15 died.
- In Group 1, 93.1% of COVID-19 participants survived at day 14 (27/29), compared to 81.2% of survivors in Group 2 (13/16) and 68.7% of survivors in Group 3 (22/32).
- At the end of the study, the proportion of participants experiencing severe COVID-19 was lower in Group 1 (10.3%) compared to Group 3 (31.3%), similar to the 14-day mortality (6.9% in Group 1 vs 31.3% in Group 3).
- In contrast, participants in Group 2 did not statistically experience less severe COVID-19 or less mortality than participants in Group 3.
- There were no outcome differences between Groups 1 and 2 for the onset of severe COVID-19, or for 14-day mortality.

Who
Seventy-seven patients consecutively hospitalized for COVID-19 in a geriatric acute care hospital unit in France.
Things to Keep in Mind
- The study participants were restricted to a limited number of hospitalized frail elderly patients who might not be representative of all older adults.
- The groups were not equally matched by sex.
- Groups 2 and 3 had a greater number of men.
- The small sizes of the groups may also have limited the statistical power of the study.
- Potential uncontrolled confounders include the lack of measurement of serum 25(OH)D at baseline to confirm vitamin D sufficiency/deficiency status and the OSCI score on admission to provide information about the severity of each case at hospitalization.
- The quasi-experimental design of the study is less robust than a randomized controlled trial.
- Patients in the comparator group did not receive vitamin D placebo and the study lacked randomization.
Author’s Conclusions
“
Irrespective of all measured potential confounders, regular bolus vitamin D3 supplementation was associated with less severe COVID-19 and better survival rates in hospitalized frail elderly. Being supplemented with 80,000 IU vitamin D3 after the diagnosis of COVID-19 was not associated with improved disease outcomes.
“
Study Design
- “Group 1” (29 patients; median age of 88 years; 69.0% women) was defined as all COVID-19 patients who had received oral doses of vitamin D supplements over the preceding year. These included doses of 50,000 IU vitamin D3 per month, or doses of 80,000 IU or 100,000 IU vitamin D3 every 2 to 3 months. None received D2 or intramuscular supplements. No patient in Group 1 received additional supplements following COVID-19 diagnosis.
- “Group 2” (16 patients; median age of 85 years; 31.3% women) was defined as COVID-19 patients usually not supplemented with vitamin D, but who received an oral supplement of 80,000 IU vitamin D3 within a few hours of their COVID-19 diagnosis.
- “Group 3” (32 patients; median age of 88 years; 40.6% women) was defined as the Comparator group, e., all COVID-19 patients who had received no vitamin D supplements, neither over the preceding year nor after the diagnosis of COVID-19.
- The primary outcome was 14-day mortality.
- The secondary outcome was each patient’s highest (e., worst) score on the 9-point World Health Organization’s Ordinal Scale for Clinical Improvement (OSCI) for COVID-19. The OSCI distinguishes between several levels of COVID-19 clinical severity according to the outcomes and dedicated treatments required, with a score ranging from 0 (no clinical or virological sign of infection) to 8 (death).
Reference
Annweiler G, Corvaisier M, Gautier J, Dubée V, Legrand E, Sacco G, Annweiler C. Vitamin D Supplementation Associated to Better Survival in Hospitalized Frail Elderly COVID-19 Patients: The GERIA-COVID Quasi-Experimental Study. Nutrients. 2020 Nov 2;12(11):3377. doi: 10.3390/nu12113377. PMID: 33147894; PMCID: PMC7693938.https://pubmed.ncbi.nlm.nih.gov/33147894/