HIGH PREVALENCE OF VITAMIN-D DEFICIENCY AND REDUCED BONE MASS IN MULTIPLE-SCLEROSIS

Background: Female patients with multiple sclerosis (MS) are at risk f or osteoporosis because of gender, immobility, and corticosteroid use. Methods: Bone mineral density (BMD) was measured by dual x-ray absorp tiometry in 80 female MS patients admitted to a tertiary care hospital . All patients completed a questionnaire that included measurements of dietary intake and sunlight exposure. Biochemical indices of bone met abolism and turnover were measured in a random sample of 52 patients, Results: BMD of the lumbar spine and femoral neck was 1 to 2 SDs lower in MS women compared with a healthy reference population. BMD was low er in patients with more severe MS. The mean 25(OH)D level of the samp le population (43 nmol/l) was in the insufficient range, and 12 patien ts (23%) had frank vitamin D deficiency (<25 nmo/l). BMD and age-relat ed BMD (z scores) at all skeletal sites measured were lowest when 25(O H)D levels were deficient. Parathyroid hormone (PTH) was frankly eleva ted in 13% of patients. PTH levels were negatively correlated with 25( OH)D levels and with BMD. Dietary intake of vitamin D was below the re commended level in 80% of patients, and 40% reported no weekly sunligh t exposure. After controlling for age, cumulative steroid use was not a determinant of BMD. Conclusions: BMD was significantly reduced in fe male MS patients, which might increase fracture risk two- to threefold . Vitamin D deficiency with secondary hyperparathyroidism is prevalent and is probably a significant cause of low BMD in this population. Vi tamin D deficiency in the female MS patient might be safely and inexpe nsively corrected by the routine use of vitamin D supplements.