The Utilization of Carotene and Vitamin A in the Rat

Abstract

Using paired feeding technique and spectrographic analytical methods, investigations have been made on the utilization of vitamin A and carotene for liver storage of this vitamin in rats. Vitamin A in cod liver oil was found to be most efficient for building up liver stores, carotene dissolved in cottonseed oil was 59% as effective, and carotene as found in alfalfa leaf meal was 21% as effective. Carotene in alfalfa leaf meal was found to be 35% as efficient as carotene dissolved in cottonseed oil for building up the rat's liver store of vitamin A. The spectro vitamin A content of the liver was found to increase significantly during the 2 weeks following weaning despite the fact that the experimental rats received a vitamin A free diet. No further significant increase occurred in the livers of litter mates that were continued on the same diet for an additional 2 weeks. Yeast present in the diet was found to contribute significantly to this increase. The importance of equalizing food intakes and using litter mates in experiments involving the relative utilization of vitamin A and carotene, is stressed particularly when chemical and physical quantitative analytical procedures are employed in conjunction with the animal experimentation.