Total body calcium in patients with inflammatory bowel disease: a longitudinal study

Serial measurements of total body calcium have been made by prompt γ-neutron activation analysis in 13 patients with inflammatory bowel disease over a mean period of 23 months. Changes in spinal trabecular bone mineral density and radial shaft bone mineral content were also assessed by using quantitative computed tomography and single photon absorptiometry, respectively. The mean annual decreases (95% confidence intervals) were: total body calcium, 7.8% (−12.0 to −3.7%; P <0.1), radial bone mineral content, 2.1% (−3.4 to −0.8%; P <0.01). No significant correlations were found between rates of change of the three variables. However, there were significant positive correlations between the baseline values for total body calcium and radial bone mineral content (r = 0.638, P <0.05), spinal bone mineral density and radial bone mineral content (r = 0.854, P <0.01), and total body calcium and spinal bone mineral density (r = 0.876, P