Vitamin D status & associations with inflammation in older adults

PLoS One. 2023 Jun 28;18(6):e0287169. doi: 10.1371/journal.pone.0287169. eCollection 2023.

Abstract

Research studies have observed associations of vitamin D with inflammation but data in representative older adult studies is lacking. We aimed to investigate the association of C-reactive protein (CRP) with vitamin D status in a representative sample of the older Irish population. The concentrations of 25-hydroxyvitamin D (25(OH)D) and CRP was measured in 5,381 community dwelling Irish adults aged ≥50 years from the Irish Longitudinal Study on Ageing (TILDA). Demographic, health and lifestyle variables were assessed by questionnaire and categorical proportions of CRP were generated by vitamin D status and age. Multi-nominal logistic regression was used to investigate the association of 25(OH)D and CRP status. The prevalence (mean; 95% confidence interval (95% CI)) of normal CRP status (0-5 mg/dL) was 83.9% (82.6-85.0%), elevated status (5-10 mg/dL) 11.0% (9.9-12.0%) and high status (>10 mg/dL) was 5.1% (4.5-5.8%). Mean (95% CI) CRP concentrations were lower in those with normal vs. deficient 25(OH)D status (2.02 mg/dL (1.95-2.08) vs. 2.60 mg/dL (2.41-2.82); p<0.0001). In a logistic regression analysis, those with insufficient or sufficient 25(OH)D status were less likely to have a high CRP status compared to those with deficient 25(OH)D status (insufficient: coefficient (CE) -0.732, 95% CI -1.12-0.33, p<0.0001; sufficient: CE -0.599, 95% CI -0.95-0.24, p = 0.001). In conclusion older adults with deficient vitamin D status had higher levels of inflammation as measured by CRP. Given that inflammation is an important pathological driver of chronic diseases of ageing, and that emerging evidence suggests that vitamin D therapy can reduce inflammation in some disease settings, optimising vitamin D status could represent an effective low risk/low-cost pathway to modulate inflammation in community dwelling older adults.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • C-Reactive Protein / metabolism
  • Calcifediol
  • Humans
  • Inflammation
  • Longitudinal Studies
  • Vitamin D Deficiency* / epidemiology
  • Vitamin D*
  • Vitamins

Substances

  • Vitamin D
  • Vitamins
  • Calcifediol
  • C-Reactive Protein

Grants and funding

Financial support was provided by Irish Government, the Atlantic Philanthropies and Irish Life plc. and the Irish Department of Agriculture, Food and the Marine (13F492).The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.