Excerpt from Natural Baby and Childcare

In the early 1990s several medical papers were published that investigated a link between the vitamin K injection and childhood leukemia. It has been suggested that vitamin K or one of the constituents, may increase the risk of childhood cancer.

As a result of this finding, many studies have been done. Most studies have not shown a significant association between vitamin K injections and cancer. However, one study concluded that they have not been able to exclude the possibility that vitamin K increases the risk of childhood cancer by up to 10%. Several case studies have found asignificant increase in the incidence of acute lymphoblastic leukemia within one to six years after birth.

Although some parents choose not to give their newborns any vitamin K, oral vitamin K is available.