Vitamin D status & associations with inflammation in older adults.
Level 4 - case-series / case-control
Cross-sectional observational analysis of cohort data
PubMed 37379302 · doi:10.1371/journal.pone.0287169
What was done
Cross-sectional analysis of 5,381 community-dwelling adults aged 50 years and older from the Irish Longitudinal Study on Ageing (TILDA). Researchers measured serum 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP), collected demographic and lifestyle variables by questionnaire, and modeled the association between 25(OH)D status and CRP categories (normal: 0–5 mg/dL, elevated: 5–10 mg/dL, high: >10 mg/dL) using multinomial logistic regression.
What was found
Overall, CRP was normal in 83.9% (95% CI 82.6–85.0%), elevated in 11.0% (95% CI 9.9–12.0%), and high in 5.1% (95% CI 4.5–5.8%) of participants. Mean CRP concentration was significantly lower in those with normal versus deficient 25(OH)D (2.02 mg/dL, 95% CI 1.95–2.08 vs. 2.60 mg/dL, 95% CI 2.41–2.82; p < 0.0001). In logistic regression, participants with insufficient 25(OH)D (coefficient -0.732, 95% CI -1.12 to -0.33, p < 0.0001) and sufficient 25(OH)D (coefficient -0.599, 95% CI -0.95 to -0.24, p = 0.001) were less likely to have high CRP compared to those with deficient status.
Why it matters
It provides large, representative population-level evidence linking vitamin D deficiency to elevated systemic inflammation in community-dwelling older adults.
Limits
The cross-sectional design cannot establish causality or exclude reverse causation, as systemic inflammation itself can lower circulating 25(OH)D concentrations. Assessment was restricted to a single inflammatory marker (CRP) in an older Irish population, limiting generalizability to other age groups and ethnicities.
Cited by
- context The Irish Longitudinal Study on Ageing (TILDA) showed that vitamin D supplementation provided health benefits.