Calcium homeostasis of an elderly population upon admission to a nursing home.

OBJECTIVE: To evaluate the skeletal health, calcium, and vitamin D homeostasis of patients upon their entry to a long-term-care facility. Factors that could contribute to the risk of future osteoporotic fractures were also evaluated.

DESIGN: Cross-sectional study.

PATIENTS: Two hundred eighty-seven consecutive admissions were invited to participate; 109 patients were recruited into the study.

MEASUREMENTS: A high prevalence of low to low-normal circulating levels of 25(OH)D was found in nursing home residents upon their admission to the nursing home, with 86% of the patients having circulating 25(OH)D levels of less than 50 nmol/L and 41% having levels below 25 nmol/L. Frankly elevated parathyroid hormone levels were found in 16% of the patients. Additionally, alkaline phosphatase and osteocalcin levels were elevated in 23% and 13% of the patients, respectively. Bone mineral measurements were in the osteoporotic range for 85% of the nursing home residents. Bone density results for females with a history of any classic osteoporotic fracture were significantly lower than for those with no fracture history (68.5 arbitrary units (AU) for those with no fracture history, 58.8 AU in those with history of hip fracture; P < 0.05). The bone mineral measurements were higher in women with adequate 25(OH)D compared with women with deficient or borderline 25(OH)D with and without fracture history. Levels of 25(OH)D were positively correlated with urine calcium/creatinine (r = .24; P = 0.03) and 1,25(OH)2D (r = .28; P = 0.01) and were negatively correlated with 1-84 PTH (r = -.24; P = 0.02).

CONCLUSION: Hypovitaminosis D is prevalent among elderly patients entering a nursing home with secondary hyperparathyroidism and apparently increased bone turnover present in patients with circulating 25(OH)D levels below 50 nmol/L. Bone density measurements showed that a majority of the individuals entering a nursing home are osteoporotic. There is a positive association between 25(OH)D levels and bone mass and a negative association between 25(OH)D levels and a history of fracture.