A warning needs to be given pediatricians and obstetricians about using unduly large doses of any water soluble vitamin K preparation in premature infants. Communications appearing in Lancet report fatal hemolytic anemia occurring in two small series of infants. The vitamin K was given in one on more doses of 10 mg. to these premature infants. No evidence of blood group incompatibility or Rh factor problem was found.
A further report appeared in substantiation of the hemolytic effect of very large doses (100 mg./kg.) of water soluble vitamin K given to rats. This hemolysis occurred only in rats deprived of vitamin E. It is known that vitamin E deficiency in rats leads to abnormally great hemolytic tendency.