Vitamin A refers to the preformed retinoids and provitamin A carotenoids that can be converted to vitamin A activity. Retinoids is a collective term for the biologically active forms of vitamin A, and they exist in 3 forms: retinol, retinal, and retinoic acid.
Vitamin A is categorized as a fat-soluble vitamin. Fat-soluble vitamins are absorbed along with dietary fat. Thus, adequate absorption of fat-soluble vitamins depends on the efficient use of bile and pancreatic lipase in the small intestine to digest dietary fat. Under optimal conditions, about 40 ro 90% if the fat-soluble vitamins are absorbed when they’re consumed in recommended amounts….