Vitamin A, an antioxidant, helps protect brain cells from harmful free radicals and benefits the circulatory system so blood flow to the brain remains strong. Vitamin A is essential to memory and learning. It also promotes healthy cells and tissues.
Vitamin A comes in several forms. Retinol, known as preformed vitamin A, is found in animal foods. Another form of vitamin A is a group called carotenoids, which includes beta-carotene. Beta-carotene is the carotenoid most readily converted by the body into vitamin A.
Foods rich in vitamin A (retinol) include beef liver, fish oil, and fortified foods such as milk. Foods rich in vitamin A (beta-carotene) include sweet potatoes, carrots, kale, spinach, apricots, cantaloupe, broccoli, and winter squash.
Most supplements break down vitamin A into beta-carotene and retinol on their labels. Too much retinol can lead to headaches, dry and scaly skin, bone and joint pain, liver damage, vomiting, loss of appetite, abnormal bone growth, nerve dam- age, and birth defects. Even though beta-carotene is not toxic to the body, it’s better not to overdo it. Vitamin A has a UL (upper limit) set at 3,000 micrograms (mcg) or 10,000 IU (international units) per day for adults over eighteen.