Abnormalities of vitamin D and calcium metabolism after surgical treatment of morbid obesity: a study of 136 patients.

Objective: To assess the effect of bariatric surgical treatment of morbid obesity on bone mineral metabolism.

Methods: We analyzed pertinent vitamin D and calcium metabolic variables in 136 patients who had undergone a malabsorptive bariatric operation. Measurements of bone mineral density (BMD), serum 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D [1,25-(OH)2D], parathyroid hormone (PTH), calcium, phosphorus, and alkaline phosphatase were performed.