Vitamin A is a fat-soluble vitamin that occurs in two forms in nature. It is found in its true form (also called retinol) in animal foods such as fish oils and liver. The body readily uses this form. Vitamin A can be found in vegetables in the form of beta-carotene (provitamin A). This form is found in plants and is the precursor of the actual vitamin. Beta-carotene has to be converted in the body in order to be used by it. Fat and bile are needed for the conversion. The liver regulates the blood level of vitamin A. It needs a special protein carrier to be transported throughout the body. An adequate protein and fat intake is required for a good absorption of vitamin A.