Dietary calcium intake and its relation to bone mineral density in patients with inflammatory bowel disease

Objectives. To investigate calcium intake and its association with bone mineral density (BMD) and the type and extent of the disease in patients with inflammatory bowel disease (IBD).
Setting. University hospital clinic.
Subjects. A total of 152 unselected IBD patients and 73 healthy controls.
Measurements. Dietary calcium intake was assessed with a food frequency questionnaire and BMD of the lumbar spina and proximal femur was measured.
Results. The IBD patients had lower dietary calcium intake (1034 [SD 493] mg) than the controls (1334 [514] mg, P <0.001). The difference was significant in the males (1047 [552] mg and 1575 [586] mg, respectively, P <0.001), but not in the females (1020 [422] mg and 1112 [303] mg). The dietary daily calcium intake was below 1000 mg in 53% of the patients and 27% of the controls ( P = 0.0004) and below 400 mg in 9.2% of the patients and none of the controls ( P =0.007). The calcium intake was not associated with the severity or the type of IBD. Seventy-one (47%) patients and eight (11%) controls avoided lactose in their diet ( P < 0.001). In the IBD patients, no association between the calcium intake and BMD was detected, whereas in the controls a positive correlation between the calcium intake and the BMD of the proximal femur was found.
Conclusions. Calcium intakes below the recommendations are seen more often in the IBD patients than in the healthy controls, but in the IBD patients the calcium intake is not associated with BMD in a cross-sectional study. A low-lactose diet is common among IBD patients. To reduce the risk of inadequate calcium intake, unnecessary dietary restrictions concerning, e.g. milk products, should be avoided for these patients.