[Gastrointestinal diseases and osteomalacia].

Osteomalacia is a metabolic bone disease associated with impaired mineralization of the bone due to Vitamin D and Calcium deficiency that can develop in gastrointestinal disorders. Gastrointestinal malabsorption after surgery, in disorders of the small bowl, in diseases of the hepatobiliary tree and in pancreatic insufficiency can lead to decreased enteral resorption of the fat-soluble Vitamin D and/or depletion of endogenous Vitamin D stores due to abnormal enterohepatic circulation. As a consequence of the Vitamin D deficiency in combination with the underlying condition patients develop an impaired calcium absorption resulting in hypocalcaemia, which leads to defective bone mineralization. Additionally chronic gastrointestinal inflammation and corticosteroid therapy - which is often needed in these patients - have a negative effect on bone metabolism as well. The therapy consists of oral substitution of Vitamin D and Calcium as well as sufficient sun light exposure or in severe cases the use of artificial UVB-radiation.