Do infants with cow's milk protein allergy have inadequate levels of vitamin D?

Abstract Objective To verify whether infants with cow's milk protein allergy have inadequate vitamin D levels. Methods This cross-sectional study included 120 children aged 2 years or younger, one group with cow's milk protein allergy and a control group. The children were recruited at the pediatric gastroenterology, allergology, and pediatric outpatient clinics of a university hospital in the Northeast of Brazil. A questionnaire was administered to the caregiver and blood samples were collected for vitamin D quantification. Vitamin D levels Results Infants with cow's milk protein allergy had lower mean vitamin D levels (30.93 vs .35.29 ng/mL; p  = 0.041) and higher deficiency frequency (20.3% vs .8.2; p  = 0.049) than the healthy controls. Exclusively or predominantly breastfed infants with cow's milk protein allergy had higher frequency of inadequate vitamin D levels ( p  = 0.002). Regardless of sun exposure time, the groups had similar frequencies of inadequate vitamin D levels ( p  = 0.972). Conclusions Lower vitamin D levels were found in infants with CMPA, especially those who were exclusively or predominantly breastfed, making these infants a possible risk group for vitamin D deficiency.