Alterations in vitamin A metabolism during zinc deficiency and food and growth restriction.

The purpose of these experiments was to further elucidate the effect of the trace element, zinc, on vitamin A metabolism. Three experiments were conducted at two different locations using different sources of animals. A total of 95 rats were used; 71 specific pathogen free and 24 germfree. The results indicate that plasma vitamin A is depressed in zinc deficient animals or animals severely restricted in food and growth. Liver stores of vitamin A were adequate in both groups. Thus, the normal mechanism for maintaining plasma vitamin A appears to be altered by either zinc deficiency and/or severe food and growth restriction.