The purpose of this study is to determine growth and protein status of infants with cow's milk protein allergy and treated with a newly innovated amino acid formula compared to those with a commercial amino acid formula.

Severe cases of cow's milk protein allergy are treated with the amino acid formula. The amino acid formula is composed of essential and non-essential amino acids, vegetable oils with or without MCT oil, and glucose polymer from various carbohydrate sources. Such formula is also fortified by minerals, trace elements,and vitamins.

Inclusion Criteria:

• Singleton
• Clinical diagnosis of cow's milk protein allergy

Exclusion Criteria:

• Other diseases

• population who are diagnosed cow's milk protein allergy via a double-blind placebo-controlled food challenge and consume either a newly innovated amino acid formula or a commercial amino acid formula
• population from a well-baby clinic