Body composition and bone mineral density (BMD) were studied by X-ray absorptiometry in 20 untreated and 12 treated women with celiac disease, as well as in 85 age-matched control women. Untreated patients had a significantly lower body weight, fat mass, lean tissue mass and BMD at the lumbar spine and total skeleton compared to controls (p < 0.001 for all parameters). Treated patients had also a significantly lower body weight (p < 0.01) fat mass (p < 0.05) and bone mineral density at lumbar spine and total skeleton (p < 0.05) compared with controls, but lean tissue mass was not diminished. However, treated patients had a significantly higher body weight, fat mass and BMD of the total skeleton compared with untreated celiac patients (p < 0.01 for all parameters). Serum alkaline phosphatase levels were increased in untreated patients but serum 250HD was normal. In conclusion, celiac disease causes a global and almost universal reduction of fat mass and BMD. The results of this cross-sectional study suggest that osteopenia does not seem to be completely restored by adequate treatment. Alteration of vitamin D metabolism was not the cause of osteopenia in the majority of patients.