Objective: We compared bone structure and body composition in adolescents with a challenge-confirmed cow's milk allergy (CMA) during infancy to peers with refuted CMA and to controls.
Design: An observational clinical cohort study.
Setting: A tertiary allergy clinic at Helsinki University Hospital.
Patients: From a randomised controlled trial from 1999 to 2001 evaluating the effect of probiotics on atopic eczema, we followed up participants (n=81) at 15-18 years' age and recruited age-matched controls (n=49). Original study participants all had atopic eczema, and CMA confirmed (n=43) or refuted (n=38) by double-blind placebo-controlled cow's milk challenge in infancy.
Main outcome measures: The primary outcome was differences in volumetric bone mineral density (vBMD) measured with peripheral quantitative CT. Secondary outcomes were differences in body composition by a bioelectric impedance analysis.
Results: Participant's median age was 17.3 years, 62% were females. After adjusting for sex, age-adjusted body mass index, past 5 years' mean daily supervised physical activity, daily vitamin D intake from food and supplements and mean daily intake of dairy products, the CMA-confirmed group had, compared with the CMA-refuted group, lower median total vBMD at the distal radius (Z-scores -1.49 vs -0.78). The CMA-confirmed group had lower median total vBMD (Z-scores -0.05 vs +0.01) and lower median trabecular vBMD (Z-scores +0.20 vs +0.51) at the distal tibia compared with controls. No group differences in body composition were found.
Conclusion: An early childhood history of CMA may be associated with lower adolescent radial and tibial vBMD. Further studies are needed to assess this potential association.
Keywords: Adolescent Health; Endocrinology.
© Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY. Published by BMJ Group.