Vitamin D deficiency and related factors in patients with osteoporotic hip fracture

BACKGROUND AND OBJECTIVE: Hypovitaminosis D is frequent in the elderly, and it is especially prevalent among patients with hip fracture. The prevalence of vitamin D deficiency and its related actors are not well known in our population. The objective of this study was to determine the prevalence of hypovitaminosis D in patients with osteoporotic hip fracture and to analyze which factors are associated with this deficit. PATIENTS AND METHOD: Transversal study. Inclusion of all consecutive patients older than 65 years, admitted in our hospital with osteoporotic hip fracture during the period of March 2002-February 2003. The prevalence of hypovitaminosis D and secondary hyperparathyroidism were analysed. Sunlight exposure, functional and nutritional status, and presence of comorbidity were investigated. RESULTS: 324 patients were included. Mean (standard deviation) age was 83 (7) years, and 80% were female. Vitamin D deficiency was observed in 217 cases (67%; 95% confidence interval [CI], 62-72%); and 57% of these patients had secondary hyperparathyroidism. A low nutritional status -albumin < 4 g/l (odds ratio [OR] = 4.5; 95% CI, 1.3-16; p = 0.019)- and a low functional status (Barthel index < 60; OR = 3; 95% CI, 1.3-6.7; p = 0.008) - were factors independently associated with hypovitaminosis D. However, an active sunlight exposure was a protective factor (OR = 0.09; 95% CI, 0.02-0.5; p = 0.004). CONCLUSIONS: The prevalence of hypovitaminosis D is high in patients with osteoporotic hip fracture, and in more than a half of the cases a secondary hyperparathyroidism is observed. The vitamin D deficiency is especially prevalent among patients with low sunlight exposure and low nutritional and functional status.