HYPOVITAMINOSIS-D IN MEDICAL INPATIENTS

Background: Vitamin D deficiency is a major risk factor for bone loss and fracture. Although hypovitaminosis D has been detected frequently in elderly and housebound people, the prevalence of vitamin D deficien cy among patients hospitalized on a general medical service is unknown . Methods We assessed vitamin D intake, ultraviolet-light exposure, an d risk factors for hypovitaminosis D and measured serum 25-hydroxyvita min D, parathyroid hormone, and ionized calcium in 290 consecutive pat ients on a general medical ward. Results A total of 164 patients (57 p ercent)were considered vitamin D-deficient (serum concentration of 25- hydroxyvitamin D, less than or equal to 15 ng per milliliter), of whom 65 (22 percent) were considered severely vitamin D-deficient (serum c oncentration of 25-hydroxyvitamin D, <8 ng.per milliliter). Serum 25-h ydroxyvitamin D concentrations were related inversely to parathyroid h ormone concentrations. Lower vitamin D intake, less exposure to ultrav iolet light, anticonvulsant-drug therapy, renal dialysis, nephrotic sy ndrome, hypertension, diabetes mellitus, winter season, higher serum c oncentrations of parathyroid hormone and alkaline phosphatase, and low er serum concentrations of ionized calcium and albumin were significan t univariate predictors of hypovitaminosis D. Sixty-six percent of the patients who consumed less than the recommended daily amount of vitam in D and 37 percent of the patients with intakes above the recommended daily amount were vitamin D-deficient. inadequate vitamin D intake, w inter season, and housebound status were independent predictors of hyp ovitaminosis D in a multivariate model. In a subgroup of 77 patients l ess than 65 years of age without known risk factors for hypovitaminosi s D, the prevalence of vitamin D deficiency was 42 percent. Conclusion s Hypovitaminosis D is common in general medical inpatients, including those with vitamin D intakes exceeding the recommended daily amount a nd those without apparent risk factors for vitamin D deficiency. (C) 1 998, Massachusetts Medical Society.