Bone mineralization in children and adolescents with a milk allergy

Abstract

To evaluate the correlation between dietary calcium intake and mineralization of the immature skeleton 55 children and adolescents aged 5-14 years (mean, 9.5 years) with a positive radioallergosorbent test (RAST) for serum antibodies to cow's milk protein were evaluated. Bone mineral density (BMD) in the lumbar spine and proximal femurs were measured by dual energy X-ray absorptiometry. BMD at each site for each subject was converted to an age-adjusted Z score based on our own series of 95 normal pediatric controls. Calcium intake was determined using a detailed food frequency questionnaire administered by a nutritionist during a 30-40-min interview. Dietary adjustments to the condition varied and resulted in a wide range of calcium intakes. Calcium supplements were taken by 22% of the subjects and were included in the determination of daily calcium intake. The group of 55 subjects was divided into quartiles based on calcium intake (mean +/- S.E mg calcium/day): Group 1, 409 +/- 21, Group 2, 663 +/- 16, Group 3, 950 +/- 32, Group 4, 1437 +/- 124. Bone density Z scores in the proximal femur serially increased across the calcium intake groups (mean +/- S.E.): Group 1, -0.16 +/- 0.31; Group 2, 0.05 +/- 0.33; Group 3, 0.44 +/- 0.24; Group 4, 0.79 +/- 0.41 (P = 0.03). A similar pattern was found with lumbar spine BMD Z scores: Group 1, -0.16 +/- 0.27; Group 2, 0.10 +/- 0.21; Group 3, 0.18 +/- 0.20; Group 4, 0.30 +/- 0.25 (P = 0.05). These data add further to the evidence that dietary calcium intake is important for optimal mineralization of the growing skeleton.