Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid and several provitamin A carotenoid (most notably beta-carotene). Vitamin A is important for normal vision, the immune system, skin health and reproduction. It also helps the heart, lungs, kidneys, and other organs work properly. There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products. The second type, provitamin A, is found in fruits, vegetables and other plant based products.
The amount of vitamin A you need depends on your age and gender. Foods high in Vitamin A are: sweet potato, carrots, tuna, butternut squash, spinach, cantaloupe, lettuce, red bell peppers, broccoli and grapefruit. Lack or over dose of vitamin A can lead to bleeding from gum or sore mouth, diarrhea, dizziness or drowsiness, double vision, severe headache, severe irritability, peeling of skin, vomiting, mood changes and hair loss.
Taking high doses of vitamin A may increase the risk of osteoporosis and hip fracture, especially in older adults and postmenopausal women.