Functions maintains integrity of epithelial membranes maintains resistance to infections necessary for formation of rhodopsin and prevention of night blindness Deficiency Mild retarded growth increased susceptibility to infection abnormal function of gastro intestinal, genitourinary, and respiratory tracts due to altered epithelial membranes dry, shriveled, thickened skin, sometimes pustule formation night blindness Severe Xerophthalmia, a characteristic eye disease, and other local infections Characteristics fat-soluble not destroyed by ordinary cooking temperatures destroyed by high temperatures when oxygen is present marked capacity for storage in liver carotene is a precursor to vitamin A Good Sources Natural Retinol milk fats butter, cheese, cream, whole milk egg yolks liver fatty fish Carotene vegetables green leafy especially escarole, kale, and parsley green, yellow, orange, or red especially carrots fruits yellow and red Food Quantity mcg RAE Egg 1 medium 118 Milk (non-fat) 1 cup 149 Nectarine 1 medium 50 Watermelon 1 piece 27 Artificial irradiated fish oils, including fish liver oil Recommended Daily Allowances (RDA) Males (11 yrs. and older) 900 mcg RAE 1,000 mcg retinol equivalents Females (11 yrs. and older) 700 mcg RAE 800 mcg retinol equivalents Pregnant females 1,000 mcg retinol equivalents Lactating females 1,200 mcg retinol equivalents Children 400-700 mcg retinol equivalents Infants 400 mcg retinol equivalents Varied values reflect different references Tolerable Upper Intake Levels (UL) Adults (19 to 50 yrs) 3000 mcg RAE Intakes above UL may lead to negative health consequences. Excessive intake of carotene, from which vitamin A is formed, may produce yellow discoloration of the skin (carotenemia). Supplementation Not recommended, since toxic in high doses. Excessive supplementation may also cause osteoporosis and increase risk of cancer. Also see detailed report of Vitamin A.