influence of renal function on vitamin D metabolism in the very elderly

OBJECTIVES: Hypovitaminosis D and chronic kidney disease (CKD) are highly prevalent in older adults. The factors correlating with 25-OH-vitamin D and PTH levels were analyzed in older adults with and without CKD. DESIGN: We performed a cross-sectional analysis embedded within the BELFRAIL study. SETTING: A population-based prospective cohort study of the very elderly in Belgium. PARTICIPANTS: 325 participants, all aged 80 or older. MEASURMENTS: Time of year and LAPAQ score were used as proxies for sunshine exposure. Vitamin D3 supplementation, gender, institutionalisation, age, level of education, and serum calcium and phosphorus level were examined as possible confounders in the analyses. RESULTS: There was no correlation between the presence of CKD and low 25-OH-vitamin D levels, but there was a significant (p