Study Group Inclusion Criteria:  had a diagnosis of CMA by OFC, except children with known anaphylaxis those on a CME diet or a specialized infant formula for at least three months had reintroduced cow's milk for at least three months ago. Children who excluded other foods in addition to cows' milk in the first four years of life for ≥ three months and who currently introduced these foods for at least ≥ three months were also enrolled in the CME group.  Healthy group inclusion criteria:  did not have CMA and other allergic diseases who had never been on a diet throughout their lives.  Exclusion Criteria:  Known acute (e.g., influenza) or chronic (e.g., diabetes, immune deficiencies ) diseases, history of systemic steroid use > 0.5 mg/kg for more than one week in their life, recurrent infections within the last three months, food restriction other than food allergy (e.g., vegan, vegetarian), moderate to severe asthma, and other medical or surgical conditions which might affect nutrition and growth.