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.