Abstract
Vitamin A overdose is a common occurrence due to food fortification and ingestion of vitamin A supplements. Vitamin A is a nutrient that possesses known and potential effects on general health and the immune response. This research work is an in vivo investigation of the effects of administration of vitamin A above dietary requirements on some organs involved in immunity, vitamin A storage, and metabolism in healthy male rats. A total of 60 young adult male Wistar rats were equally divided into three groups. Rats in the two test groups were orally administered with vitamin A at different concentrations (8000 and 15 000 IU kg(-1) body weight) for 21 days, while the control rats did not receive any supplementation. Weekly body weights and weights of the liver, kidney, spleen, and thymus were measured. Histological evaluations were carried out on the liver, kidney, thymus, and Peyer's patches. Findings show that vitamin A did not significantly affect body and organs' weights, except for a significant decrease of spleen weights for both experimental groups. Vitamin A was found to lead to some changes in the histology of the tested organs. This is the first study of its kind and sets a base for future studies.