REGULATION OF CALCIUM AND BONE METABOLISM AFTER GASTRECTOMY

Gastrectomy resulted clinically and in an animal model in a reduced se rum calcium and 25-(OH)-vitamin D, that was counterregulated by increa ses of parathyroid hormone and 1,25-(OH)(2)-Vitamin D. Both are known to increase bone resorption. In accordance to this, bone mineral densi ty was decreased after gastrectomy. Our data indicate that a reduced s erum calcium after gastrectomy activates counterregulatory mechanisms resulting in bone mass loss. Whether calcium and vitamin D supplementa tion after gastrectomy prevents postgastrectomy bone mass loss by supp ressing endogenous release of parathyroid hormone and production of 1, 25-(OH)(2)-vitamin D is currently under investigation.