Vitamin A is essential for all vertebrates. Birth defects may occur with either deficiency or excess vitamin A. High levels of vitamin A occur in some commercial cat foods due to the use of liver. Toxicity, teratogenicity, and metabolism of vitamin A were the focus of the research. The first objective was to define a safe upper level of vitamin A for cats during gestation. It was demonstrated that a high level of vitamin A added to the diets had potential to cause birth defects in the kittens, but not toxicity in the queen. The second study examined chronic vitamin A toxicity in female cats. It was found that cats in this study consumed far more vitamin A per kg body weight and had fewer signs of toxicity than reported cases in other species. A tracer was used to investigate whether cats given diets with high levels of vitamin A had the ability to safely metabolize excess vitamin A. Cats given a high vitamin A diet were able to efficiently remove it from plasma. Pet food manufacturers should find this information useful for formulating healthy cat foods for both gestating queens and adult cats.