. . . "Examples of vitamin A include vitamins A such as retinol, vitamin A1 alcohol, retinal, vitamin A1 aldehyde, vitamin A1 acid, 3-dehydroretinal, vitamin A2 alcohol, 3-dehydroretinal and vitamin A2 aldehyde; provitamins A such as ??-carotene, ??,??-carotene, ??-carotene, ??,??-carotene, ??-carotene and ??,??-carotene; and cisvitamins A." .