PURPOSE OF THE STUDY.
The purpose of this study was to identify the effects of dietary calcium restriction on bone mineral density (BMD) in young adults with cow’s milk allergy (CMA) and to determine if other dietary calcium intake can compensate for lack of diary intake.
Patients with IgE-mediated CMA (group I, n = 33) diagnosed in infancy were compared with 24 matched but milk-tolerant patients (Group II). In addition, they were compared with 12 CMA allergic patients who underwent oral milk desensitization (Group III) and consumed ≥4.5 g milk protein daily. Patients were all Tanner V and ranged from 16.5 to 30 years old.
Serum levels of 25-OH vitamin D3, calcium, phosphorus, magnesium, and parathyroid hormone were quantified. BMD was measured in the lumbar spine (SP), femoral neck (FN), and hip.
There were no differences in the serum markers between groups with the exception of Group I having a higher PTH level than Group III, but both groups had normal PTH levels. The mean vitamin D level was nearly sufficient in all groups. Interestingly, more subjects in Group II (65%) had levels <30 ng/dL than in Groups I (50%) or III (41%). The average BMD T score was significantly lower in all 3 locations in Group I, although bone calcium content was not different. Of the CMA group, 27% had osteoporosis with t scores > –2.5 SD. None of Groups II or III was osteoporotic. Interestingly, there was a comparable rate of osteopenia in Groups I and II (60.7% and 62.5%, respectively). Only 33.3% of Group III had osteopenia with BMD > –1.1 SD. Dietary calcium intake correlated with BMD of the hip and FN but not the SP.
Patients with CMA have significant risk of osteoporosis at a young age that appears to be reversible after milk desensitization and regular milk consumption.
There are a few important points to be made from this study. First, because most CMA is diagnosed in very young children, we must be sure our CMA patients get adequate calcium in their diets starting early in life. Other dietary sources do not seem to be adequate to compensate for the lack of milk. Similarly, vitamin D levels should be monitored. This study was conducted in Israel where there is greater sun exposure than in many parts of the United States. The average levels measured herein were higher than in NHANES and other US population studies. Patients without CMA had a higher rate of osteopenia than Group III (with regular milk consumption) because they had limited dairy consumption themselves. Most (75%–80%) dietary calcium intake in the United States comes from dairy. So let’s get back to after-school milk and cookies for children tolerant of milk! Finally, I remind readers that oral desensitization to milk (Group III) is still a research tool and is not ready for prime time.
- Copyright © 2015 by the American Academy of Pediatrics