Effects of Vitamin B12 on the Utilization of Carotene and Vitamin a by the Rat

Abstract

Young albino rats deficient in vitamin A and vitamin B₁₂ were supplemented daily for 21 days with moderate amounts of either carotene or vitamin A dissolved in cottonseed oil. The intramuscular injection of vitamin B₁₂ (Cobione, Normocytin, or liver extract) with or without sulfasuxidine in the diet increased both growth and tissue deposition of vitamin A from carotene fed. An APF supplement was likewise effective in increasing the utilization of carotene for storage of vitamin A. On the other hand, the vitamin was comparatively ineffective with respect to the utilization of preformed vitamin A for storage, but the growth rates of the vitamin B₁₂-supplemented animals were greater. The results of this investigation suggest that the concomitant administration of vitamin B₁₂ and carotene and perhaps vitamin A may exert beneficial effects on the nutritional state of animals in regard to vitamin A needs. The significance of these observations is discussed in regard to a possible mode of action of vitamin B₁₂ on carotene and vitamin A metabolism.