Takeaway
- Vitamin D deficiency was associated with an increased risk of severe SARS-CoV-2 infection requiring hospital admission.
- However, no association was observed between vitamin D deficiency and excess mortality in COVID-19.
Why this matters
- Findings highlight urgent action to address the high prevalence of vitamin D deficiency that increases COVID-19-related morbidity.
Study design
- A retrospective case-control study included 79,602 participants with results of serum 25-hydroxyvitamin D (25[OH]D) between April 2019 and January 2021.
- Of these, 58,368 participants were recruited to the primary cohort and 21,234 to the validation cohort.
- Vitamin D levels were classified as deficiency (<25 nmoL/L) and insufficiency (25-50 nmoL/L).
- Funding: None.
Key results
- In the primary cohort:
- Overall, 1036 (1.8%) participants were hospitalised with COVID-19, of whom 375 (36.2%) died.
- Median serum 25(OH)D level was 50.0 (interquartile range [IQR], 34.2-66.9] nmoL/L in non-hospitalised patients vs 35.0 (IQR, 21.0-57.0) nmoL/L in hospitalised patients (P<.005).
- In the validation cohort:
- Overall, 772 (3.6%) participants were hospitalised with COVID-19, of whom 295 (38.2%) died.
- Median serum 25(OH)D level was 47.1 (IQR, 31.8-64.7) nmoL/L in non-hospitalised patients vs 33.0 (IQR, 19.4-54.1) nmoL/L in hospitalised patients (P<.005).
- Low vitamin D level (25[OH]D <50 nmol/L) was associated with increased odds of hospitalisation with COVID-19 in both (OR; 95% CI):
- primary cohort (2.22; 1.93-2.53; P<.005); and
- validation cohort (2.16; 1.83-2.54; P<.005).
- There was no association between low vitamin D levels and in-patient hospital mortality from COVID-19 in either cohort.
Limitations
- Retrospective design.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.
