What is lactose intolerance? Does my baby have it?
Lactose intolerance is caused by a deficiency of lactase. Fortunately, significant lactase deficiency is extremely rare in infants. Infants born with severe lactose intolerance would not have survived before lactose-free products were invented in this century. As children age into adulthood, lactose intolerance becomes much more common. In some ethnic groups, nearly all adults have at least mild lactose intolerance.
