Factors Influencing Dietary Vitamin K Requirements of Rats and Mice

Abstract

The literature concerning the dietary requirements of rats and mice for vitamin K has been reviewed and some relevant observations on the breeding colony of rats at Carworth Europe are reported. From the literature cited it is concluded that the true vitamin K requirement, that is, the amount that must be absorbed to prevent prolongation of prothrombin time, is influenced by many factors; the most important are strain, age, sex and environmental temperature. In determining the amount of a particular form of vitamin K that must be included in the diet of a given strain of rat or mouse in a given environment, the principal factors to be considered are the degree of coprophagy, the level of vitamin A and the amount and types of fats and proteins present in the diet.