Dairy consumption and vitamin D concentration in adolescents with challenge-confirmed cow's milk allergy during infancy

Abstract

Background/objectives: Milk is an important source of dietary calcium and, if fortified, vitamin D. Cow's milk allergy (CMA) is treated with a milk elimination diet. Although most children become tolerant by age 3 years, some continue dairy avoidance. It remains unclear whether adolescents with a history of CMA adopt similar milk consumption as their peers. We assessed dairy consumption and concentration of serum 25-hydroxyvitamin D (25(OH)D) in adolescents with either confirmed CMA or a negative CMA challenge in infancy (CMA-refuted group) and age-matched controls.

Subjects/methods: This study is based on a previously reported randomized controlled trial from 1999 to 2002 on the treatment effect of probiotics on atopic eczema in participants aged <12 months (n = 230) with data on CMA status. We followed up these participants, aged 15-18 years, in 2017 (n = 104). A 20-item food frequency questionnaire assessed dairy consumption. An automated immunoassay measured 25(OH)D concentration.

Results: Median dairy product consumption did not differ between adolescents with CMA (449 g/d, n = 40), the CMA-refuted group (566 g/d, n = 36), and controls (235 g/d, n = 51) (P = 0.117). Median 25(OH)D concentrations were 76.0, 79.3, and 80.8 nmol/l, respectively (P = 0.844). Among participants, 93% were vitamin D sufficient (25(OH)D ≥ 50 nmol/l), with no differences between groups (P = 0.914).

Conclusion: Among adolescents with a history of CMA during infancy, our study found no reintroduction failure of milk and no difference in vitamin D insufficiency rate compared with peers. Current management of CMA seems to adequately minimize later nutritional disadvantages associated with a cow's milk elimination diet.

Fig. 1. Flowchart of the study.

AE atopic eczema, Q1 questionnaire one, Q2 questionnaire two, CMA cow’s milk allergy—positive, double-blind, placebo-controlled, oral cow’s milk challenge during the original study; CMA refuted: negative, double-blind, placebo-controlled, oral cow’s milk challenge during the original study. Inclusion criteria for the original study were: 1. age <12 months at the beginning of the study; 2. symptoms suggestive of CMA, the required symptom being AE; 3. no regular use of probiotic preparations (longer than 1 week within 6 weeks prior to the beginning of the study).

Fig. 2. Vitamin D, calcium and phosphate levels in the three study groups; CMA, CMA refuted and control.

All individual measures are plotted by group (circle = cow’s milk allergy (CMA) confirmed during infancy, CMA (n = 43); square = CMA refuted during infancy, CMA refuted (n = 38); triangle = control (n = 50)): (A) serum 25-hydroxyvitamin D concentration (nmol/l); (B) plasma calcium level (mmol/l); (C) plasma inorganic phosphate level (mmol/l). Lines represent median values. Groups were compared by the Kruskal–Wallis test; no differences between groups were significant.