[Prevalence of hypovitaminosis D in elderly institutionalized residents: influence of a substitutive treatment]

Abstract

Background: Osteoporosis in the elderly is a common and severe disease, vitamin D deficiency being an important causative factor. Hypovitaminosis D is frequent in old people, particularly those living in nursing homes.

Subjects and method: We performed a cross-sectional study of 100 randomly recruited elderly institutionalized subjects. The prevalence of hypovitaminosis D and its possible repercussion on the phosphocalcium metabolism were assessed. The degree of sun exposure and the existence of co-morbidity were also recorded. Individuals with hypovitaminosis D were included in a longitudinal study (6 months' duration) aimed at assess the efficacy of treatment with calcium and two different therapeutic regimens with calcidiol (16,000 IU/week or 16,000 IU every 3 weeks).

Results: 87% of individuals had hypovitaminosis D; 21.8% of them had secondary hyperparathyroidism. The study population had a low degree of sun exposure and a high level of co-morbidity. The two doses of calcidiol led to a normalization of 25-OHD3 levels, increased calciuria and compensated secondary hyperparathyroidism, yet higher 25-OHD3 levels were achieved with the weekly therapeutic scheme.

Conclusions: Hypovitaminosis D prevalence appears to be very high In the elderly institutionalized population. Calcium and calcidiol supplementation normalized 25-OHD3, improved calcium absorption and compensated secondary hyperparathyroidism. Calcium and vitamin D supplementation should be employed routinely in the elderly institutionalized population.