VITAMIN A, ITS SOURCES AND BENEFITS

Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids.

Currently listed on the Nutrition Facts label, Vitamin A is measured in international units (IU). The Institute of Medicine lists the Recommended Dietary Allowances (RDA) of vitamin A in micrograms (mcg) of retinol activity equivalents (RAE) to account for different absorption rates of preformed vitamin A and provitamin A carotenoids. The Recommended Dietary Allowance for adults 19 years and older is 900 mcg RAE for men and 700 mcg RAE for women.

Many breakfast cereals, juices, dairy products, and other foods are fortified with retinol (preformed vitamin A). Many fruits and vegetables and some supplements contain beta-carotene, lycopene, lutein, or zeaxanthin. Leafy green vegetables (kale, spinach, broccoli), orange and yellow vegetables (carrots, sweet potatoes, pumpkin and other winter squash, summer squash), Tomatoes, Red bell pepper, Cantaloupe, mango, Beef liver, Fish oils, Milk, Eggs and Fortified foods

Vitamin A toxicity may be more common than a deficiency, due to high doses of preformed vitamin A found in some supplements. Vitamin A is also fat-soluble, meaning that any amount not immediately needed by the body is absorbed and stored in fat tissue or the liver. If too much is stored, it can become toxic. The tolerable upper intake of 3,000 mcg of preformed vitamin A is thought to be safe.

Deficiency of Vitamin A is rare but may occur. Conditions that interfere with normal digestion can lead to vitamin A malabsorption such as celiac disease, Crohn’s disease, cirrhosis, alcoholism, and cystic fibrosis. people at risk are adults and children who eat a very limited diet due to poverty or self-restriction. Mild vitamin A deficiency may cause fatigue, susceptibility to infections, and infertility. more serious deficiency may cause Xerophthalmia, a severe dryness of the eye that if untreated can lead to blindness, Nyctalopia or night blindness, Irregular patches on the white of the eyes, Dry skin or hair

The evidence suggests that eating a variety of foods rich in vitamin A, especially fruits and vegetables, is protective from certain diseases, like lung cancer, prostate cancer and age related macular degeneration. Though the health benefit of vitamin A supplements is less clear. Vitamin A Helps your body's natural defense, against illness and infection, work properly; Helps vision in dim light,; Keeps skin and the lining of some parts of the body, such as the nose, healthy.