Vitamin D status & associations with inflammation in older adults

• Published in: PloS one Vol. 18; no. 6; p. e0287169
• Main Authors: Laird, Eamon, O’Halloran, Aisling M., Molloy, Anne M., Healy, Martin, Bourke, Nollaig, Kenny, Rose Anne
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.06.2023; Public Library of Science (PLoS)
• Subjects: 25-Hydroxyvitamin D; Adults; Aged; Aging; Alfacalcidol; Analysis; Biology and Life Sciences; Biomarkers; Body mass index; C-reactive protein; C-Reactive Protein - metabolism; Calcifediol; Calciferol; Care and treatment; Chronic diseases; Chronic illnesses; Confidence intervals; Creatinine; Cytokines; Demographic variables; Diabetes; Disease; Health aspects; Heart; Humans; Inflammation; Longitudinal Studies; Medicine and Health Sciences; Mortality; Obesity; Older people; People and Places; Physical sciences; Population; Proteins; Regression analysis; Statistical analysis; Tumor necrosis factor-TNF; Vitamin D; Vitamin D Deficiency - epidemiology; Vitamin deficiency; Vitamins; Ireland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0287169

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.