Metabolic bone disease in gastrointestinal, hepatobiliary, and pancreatic disorders and total parenteral nutrition.

Privational vitamin D deficiency is assumed to be uncommon in the developed countries because of the routine fortification of foods with vitamin D. Malabsorption of vitamin D and calcium (especially in an environment of reduced sun exposure) therefore accounts for the majority of cases of metabolic bone disease seen in patients with various gastrointestinal disorders in the United States. Yet recognition of this often asymptomatic bone disease is unsatisfactory and frequently delayed for months or even years. This results in severe irreversible bone loss, putting patients at increased fracture risk for the remainders of their lives. As evident from the small number of published reports, it is obvious that little attention is given to understanding the pathogenesis and prevention of bone disease in patients with various gastrointestinal disorders. This review will summarize recent advances in the pathogenesis, prevention, and treatment of metabolic bone disease in patients with these disorders. We propose methods for identifying bone loss in such patients so that appropriate preventive measures can be instituted to avoid significant morbidity.