Am J Clin Nutr

Low vitamin D status tied to severe respiratory infections across ethnic groups

January 23, 2026

A large UK Biobank case-control study found that adults with serum 25-hydroxyvitamin D (25[OH]D) levels <15 nmol/L had a 33% higher risk of hospitalization for respiratory tract infections (RTIs) compared with those with levels ≥75 nmol/L (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.05-1.67). The analysis included 36,258 participants across diverse ethnic groups (34% White, 28% Asian, 19% Black). Each 10 nmol/L increase in vitamin D was associated with a 4% lower HR for RTI hospitalization (0.96; 95% CI, 0.94-0.99).

Clinical takeaway: Consider assessing and addressing vitamin D deficiency—particularly in high‑risk and ethnic minority patients—as part of a broader strategy to reduce risk of severe respiratory infections.

Source:

Bournot AR, et al. (2025, December 29). Am J Clin Nutr. Association between serum 25-hydroxyvitamin D status and respiratory tract infections requiring hospital admission: unmatched case-control analysis of ethnic groups from the United Kingdom Biobank cohort. https://pubmed.ncbi.nlm.nih.gov/41475552/