The prevalence of vitamin D deficiency among seniors is high. Whereas sun exposure, vitamin D intake, genes, demographics, and lifestyle have been identified as being important determinants of vitamin D status, the impact of these factors is expected to differ across populations. To improve current prevention and treatment strategies, this study aimed to explore the main determinants of vitamin D status and its relative importance in a population of community-dwelling Dutch older adults.
Serum 25-hydroxyvitamin D (25(OH)D) was measured in 2857 adults aged =65 years. Sun exposure was assessed with a structured questionnaire (n = 1012), vitamin D intake using a Food Frequency Questionnaire (n = 596), and data on genetic variation that may affect 25(OH)D status was obtained for 4 genes, DHCR7 (rs12785878), CYP2R1 (rs10741657), GC (rs2282679), and CYP24A1 (rs6013897) (n = 2530).
Serum 25(OH)D concentrations