by Corinne Daut RN, BSN, IBCLC

As mothers, we are told that our breast milk is the perfect food for our baby and contains everything that he or she needs, so we are left puzzled when our pediatrician recommends a vitamin D supplement.  Why does the American Academy of Pediatrics (AAP) consider breast milk the optimal source of infant nutrition if it doesn’t have enough vitamin D? Is breast milk really lacking this essential nutrient?

The answer is mixed.  As humans, one of the most common ways that we get vitamin D is through exposure to sunlight. In order to do this, we require direct sunlight exposure without sunscreen.  Since direct sun exposure puts us at risk for skin cancer, mothers are advised to limit their baby’s sun exposure as much as possible, especially without sunscreen.  This means that since most babies cannot safely get enough exposure to sunlight, they need another way to get vitamin D.  Humans can also get vitamin D through dietary sources and supplements.  Many foods such as milk and cereal are fortified with vitamin D and most multi-vitamins contain vitamin D.  Still, it is believed that many mothers are not receiving enough vitamin D through their diets to make up for the lack of sun exposure. This leaves very little vitamin D to be passed through to breast milk. 

Vitamin D is an essential nutrient that helps our bodies with calcium absorption which is important for bone development. Babies who do not get enough vitamin D could develop a disorder called rickets. Rickets causes soft, weak bones, delayed growth, and sometimes skeletal deformities. To prevent rickets, it is recommended to supplement breastfed babies with vitamin D.

Both the American Academy of Pediatrics (AAP) and Academy of Breastfeeding Medicine (ABM) recommend that all babies who are exclusively or partially breastfed receive 400 IU of vitamin D daily, starting within the first few days of life.  Babies should continue receiving the vitamin D supplement until they are drinking at least 32 oz. each day of either infant formula or whole cow’s milk, as these are fortified with vitamin D.  It is important to note that cow’s milk is not recommended until 12 months of age.  You can purchase vitamin D drops over-the-counter at a pharmacy.  Some brands offer a dosage of 400 IU in 1 mL and others offer the dosage in 1 drop. The 1 drop dosage can be easier to administer.  Another option for supplementing your breastfed baby with vitamin D is to supplement yourself. If a mother chooses to supplement herself, the ABM recommends 6400 IU daily in order for enough vitamin D to pass on to her breast milk.  Most prenatal vitamins contain some vitamin D, usually 400-1200 IU, so it is important to add an additional vitamin D supplement to achieve the recommended dose.