Vitamin K & Breastfed Babies

Fat-soluble vitamin K is stored in the body’s liver and fatty tissue. Besides contributing to bone health by aiding in the utilization of calcium, vitamin K is responsible for helping blood coagulate, or clot, properly. Dietary sources include broccoli, cauliflower, cabbage, liver and dark leafy greens such as spinach and kale. The body’s main source of vitamin K, however, comes from its synthesis by bacteria in the large intestine.

Newborns

While some amount of vitamin K crosses the placenta, babies have very little of the blood-clotting vitamin in their bodies at birth and for the first several days of life. Colostrum, or first milk, is rich in vitamin K, and it’s also passed through breast milk. Until newborns have enough gut bacteria to begin producing it, however, they’re at greater risk of a deficiency that can cause hemorrhagic disease of the newborn, or HDN, also known as vitamin K deficiency bleeding, or VKDB. The life-threatening condition is preventable with an injection of vitamin K at birth.

Vitamin K Injections

The American Academy of Pediatrics and equivalent international organizations recommends all babies receive a single intramuscular injection of vitamin K at birth to avert the possibility of HDN or VKDB. In the United States, the injection is a routine component of the procedures performed on newborns. Parents who don’t want their newborn to receive an injection can request that it not be administered.

Risk Factors

Babies born to mothers who take anticonvulsant medication to prevent seizures are more likely to have a vitamin K deficiency, putting them at risk of HDN or VKDB. Premature babies are at greater risk, but usually receive a smaller dose of vitamin K by injection than full-term infants. Some health care practitioners believe that a baby’s risk of cerebral hemorrhage within days of birth is increased by having gone through a very short or very long labor. Babies born with severely cone-shaped heads from spending a prolonged amount of time in the birth canal are also at greater risk of a brain hemorrhage, as are babies whose heart rates undergo significant decelerations just before delivery. In her blog on the website BabyCenter, Dr. Susan Markel writes that breastfed babies who experience uncomplicated births don’t necessarily need a vitamin K injection, in part because colostrum is a rich source of vitamin K.

Cancer Controversy

Two retrospective studies published in the early 1990s suggested there was a correlation between the vitamin K injections administered to newborns and later development of leukemia and other childhood cancers. Two large, subsequent retrospective studies, one conducted in the United States and the other in Sweden, found no evidence suggesting a link between any type of cancer and the injections. According to Oregon State University's Linus Pauling Institute, a combined examination of six case-controlled studies also demonstrated no evidence of a link between the risk of childhood leukemia and vitamin K injections. The American Academy of Pediatrics continues to recommend all newborns receive the injection, stating that VKDB is life-threatening and cancer risks are unsubstantiated and improbable.