Although breastfed infants are more at risk for a vitamin D deficiency, experts caution that breast milk is still the best food source for infants . All the cases occurred in African-American babies who were exclusively breast fed , and the cases were so severe the infants sometimes had obvious bone abnormalities or even seizures. In Georgia, the CDC found six cases of severe rickets occurred in youngsters 7-21 months of age between January 1997 and June 1999. The children were breast-fed for at least 7 to 19 months and in one instance, a child drank an unfortified milk substitute after being weaned. Although most diagnosed cases are especially severe, doctors suspect there may be many more mild cases of the illness that go undiagnosed .
Bones become soft and weak, and typically the legs bow outwards due to the weight of the body.
The condition can lead to skeletal abnormalities, and in severe cases, seizures. The risk is especially great for darker skinned infants, who have higher levels of skin pigment, which limits the amount of vitamin D production triggered by the sun. According to the AAP, the answer may be to provide breast-fed infants, regardless of race, vitamin D supplements. In addition, adequate vitamin D levels are important for older children and adults as well. All commercially available infant formulas are fortified with vitamin D, and formula-fed infants should not be given vitamin D supplements, according to the experts, since too much vitamin D can be toxic.