Osteoporosis and eating disorders.

Osteoporosis is a common complication of anorexia nervosa. Multiple factors increase risk, including decreased body weight and fat content, elevated cortisol levels, inadequate vitamin D and calcium intake, and amenorrhea and hypoestrogenemia. There is both decreased bone formation and increased bone resorption in the osteoporosis of anorexia nervosa. Treatment includes weight normalization and supplemental calcium and vitamin D. Unlike postmenopausal osteoporosis, estrogen replacement does not prevent or correct the osteoporosis that occurs in anorexia nervosa. Patients with bulimia nervosa or an eating disorder not otherwise specified may also be at risk of osteoporosis, especially if they have had a prior episode of anorexia nervosa.