Low bone mineral density in adult patients with coeliac disease

Calcium and vitamin D malabsorption in coeliac disease (CD) predispose to skeletal demineralisation. The aim of this study was to evaluate the prevalence of bone mineral density (BMD) and calcium deficiencies in adult patients with CD and assess whether a gluten-free diet is sufficiently effective for BMD restoration.

BMD and biochemical parameters of bone and mineral metabolism were measured in 35 adult CD patients receiving (19) or not receiving (16) a gluten-free diet (GFD) and in 36 controls. Then the CD patients were treated with a GFD and calcium (1.0 g/day) plus alfacalcidol (0.25-1 μg/day) for one year.

Reduced BMD was diagnosed in 57-77% of the patients. Mean calcaemia, calciuria, and 25(OH) vitamin D were lower, but serum PTH and bone-turnover markers (ALP, osteocalcin, ICTP) were significantly higher in the CD patients than in the controls. In the patients on the diet (GFD(+)), BMD was higher than in the GFD(-) patients, but lower than in the controls. The biochemical parameters were normal in the GFD(+) patients except for diminished calciuria. Mean BMD after one year of treatment significantly increased (p < 0.05), mostly in the lumbar spine (mean: 7.3%), but decreased in five patients who did not strictly adhere to the GFD.

Deficiencies in calcium, vitamin D, and BMD are very common in adult CD patients. Gluten avoidance increased BMD, although the values remained markedly lower in several patients. Because of chronic calcium deficiency despite GFD, calcium and vitamin D supplementation in most adult CD patients is proposed.