C-reactive protein and fibrinogen of bedridden older patients in a six-month vitamin D supplementation trial

OBJECTIVE: To elucidate the association between vitamin D status, C-reactive protein (CRP) and fibrinogen. DESIGN: Secondary analysis of a randomised double-blind placebo controlled trial. SETTING: Four longterm care hospitals (1215 beds) in Helsinki, Finland. PARTICIPANTS: 218 long-term inpatients aged over 65 years. INTERVENTION: Eligible patients (n = 218) were randomized to receive 0 IU/d, 400 IU/d, or 1200 IU/d cholecalciferol for six months. METHODS: Plasma 25-hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), high sensitive CRP, fibrinogen, amino-terminal propeptide of type I procollagen (PINP), and carboxy-terminal telopeptide of type I collagen (ICTP) were measured. RESULTS: The patients were aged (84.5 +/- 7.5 years), vitamin D deficient (25-OHD = 23 +/- 10 nmol/l), chronically bedridden and in stable general condition. The mean baseline CRP and fibrinogen were 10.86 mg/l (0.12 mg/l - 125.00 mg/l) and 4,7 g/l (2.3 g/l - 8.6 g/l), respectively. CRP correlated with ICTP (r = 0.217, p = 0.001), but not with vitamin D status. Supplementation significantly increased 25-OHD concentrations, but the changes in CRP and fibrinogen were insignificant and inconsistent. The post-trial CRP concentrations (0.23 mg/l -138.00 mg/l) correlated with ICTP (r = 0.156, p < 0.001), but no association was found with vitamin D status. The baseline and post-trial fibrinogen correlated with CRP, only. CONCLUSIONS: CRP concentrations are associated with bone turnover, but not with vitamin D status, and vitamin D supplementation has no major effect on CRP or fibrinogen concentrations in bedridden older patients.