Hypervitaminosis A in rats. Varying responses due to different forms, doses, and routes of administration

Abstract

A study made on rats after excessive vitamin A treatment showed that the mortality, bone lesions, and calcification of organs are related to at least three factors, i.e., forms of vitamin A (vitamin A palmitate or vitamin A alcohol), doses (25,000, 50,000, and 75,000 international units (IU)/rat/day), and routes of administration (intraperitoneal or oral). In rats that received vitamin A palmitate by intraperitoneal route, there was no clinical toxicity, no bone lesion, nor soft tissue calcification, but oral administration of vitamin A palmitate of the same dose produced clinical toxicity with bone lesion and soft tissue calcification. Clinical toxicity, bone damage, and tissue calcification developed in animals that received vitamin A alcohol by both routes. The intraperitoneal administration produced more toxicity and more tissue damage in rats than the oral administration.