- A meta-analysis finds that vitamin D levels are positively correlated with lung function, meaning that lower levels are indicative of poorer function.
Why this matters
- Vitamin D supplements should be considered if levels are low.
- Meta-analysis of 27 studies (n>2200) after a search of OVID, MEDLINE, Web of Science, and PubMed.
- 19 studies were cross-sectional, 6 were case-control, 2 were cohorts.
- Funding: Zhejiang Province Public Welfare, China.
- Low vitamin D levels (vs sufficient levels) had lower:
- Forced expiratory volume in 1 second (FEV1; mean difference [MD], −0.1; P<.01>
- FEV1% (FEV1 expressed as a percentage of forced vital capacity [FVC]; MD, −10.02; P<.01>
- FEV1/FVC (MD, −1.52; P=.07).
- FEV1 (r, 0.12; P=.003).
- FEV1% (r, 0.19; P<.001>
- FVC (r, 0.17; P=.05).
- FEV1/FVC (r, 0.4; P<.001>
- Asthma control test (ACT; r, 0.33; P<.001>
- Observational design.
- High heterogeneity across studies.
- Many studies had small numbers of subjects.