Hypovitaminosis D and Associated Risk Factors in Postmenopausal Women

Abstract

Given the relevance of vitamin D in calcium metabolism homeostatic control, as well as its role as differentiation and cell proliferation modulator, it is important to study its circulating level in patients considered at risk, in order to develop prevention strategies. We studied 77 postmenopausal women with no history of osteoactive drug therapy, corticosteroid intake or diseases that could alter bone metabolism, attending the Menopause Center at the Hospital Provincial del Centenario, Rosario, Argentina. A medical history was taken, and a food consumption frequency questionnaire was applied in order to estimate daily calcium intake. To assess daily physical exercise, work and sports activities were investigated. Serum parathyroid hormone (PTH) and 25(OH)D were measured, and a hip DXA scan was performed in every patient. An inappropriate level of 25(OH)D was observed in 86.3% of patients. The 25(OH)D average value was found within the insufficiency range (<30 ng/ml) whereas PTH average concentration fell within the normal range, and bone mineral density average value was found within the osteopenic category. A statistically significant negative logarithmic association was observed between serum PTH level and vitamin D status (p = 0.01). Mean 25(OH)D concentration among patients who had reported fractures was significantly lower than the corresponding to women who had not suffered this type of event. Patients with vitamin D deficiency had significantly wider mean Cobb angle; higher sum of wedge angles of T4 - T12 vertebral bodies mean values, and higher uncompromised vertebrae wedge angle values than non-deficient women. This study shows high hypovitaminosis D occurrence among these postmenopausal women.