Vitamin A is an essential nutrient, which means that our bodies cannot create it and we must obtain it from our diets or supplements. Vitamin A is perhaps most well-known for its importance to our vision, but is also vital to other body systems and functions.
Function of Vitamin A
The cells in our eyes that perceive light and color require vitamin A to function properly. In fact, one of the first signs of vitamin A deficiency is poor night vision, and if left untreated, vitamin A deficiency can lead to blindness. Vitamin A supports skin cells and the development of healthy bone tissue. Vitamin A is also a required nutrient for healthy immune system functioning. It protects and supports cell membranes to help fight infection and increases white blood cell activity.
Vitamin A & Beta-carotene
In addition to vitamin A, there are dozens of other nutrients–called carotenoids–that are converted into vitamin A in the body and therefore have vitamin A “activity.” The best known of these carotenoids is beta-carotene. Beta-carotene is a non-toxic nutrient that is converted to vitamin A in the body as needed. If your body’s storage of vitamin A is adequate, beta-carotene will not be converted into vitamin A. Beta-carotene also has benefits of its own, acting as an antioxidant to protect cells in the body from free radical damage.
Beta-Carotene as a Vitamin A Supplement
It is often advised to supplement with beta-carotene rather than vitamin A because beta-carotene does not have any toxic side effects in high doses. Vitamin A, on the other hand, if taken in large doses (more than 25,000 IU per day) for a long period of time, can cause liver damage, headaches and hair loss. If you do take excess amounts of beta-carotene, you may experience the development of a temporary orange coloration of your skin. This effect is harmless and will go away if you reduce your beta-carotene intake.
Prevention of Vitamin A Deficiency
- To ensure that you are obtaining enough vitamin A, make sure that you are taking 25,000 IU of beta-carotene daily, either on its own or as part of a daily multivitamin. If you are trying to prevent getting sick during cold and flu season, you can supplement with 5,000 IU of vitamin A daily (adults only), but do not continue this dose for more than a week without consulting your doctor and always consult your doctor before taking vitamin A if you are being monitored for any health condition. Those who live with Crohn’s disease, celiac disease or other malabsorption syndromes may develop a deficiency of vitamin A, as well as other nutrients. Deficiencies may not be severe enough to attract your attention, but may prevent you from being as healthy as you can be. Speak with your doctor about your need for additional nutrient supplementation if you are being treated or monitored for any chronic health condition.
Warning: Pregnancy and Vitamin A
High levels of vitamin A taken during pregnancy can increase the risk of birth defects, including heart and nervous system abnormalities, especially during the first trimester. It is therefore important to avoid direct vitamin A supplementation if there is the potential for you to become pregnant or if you are actively trying to conceive. Because vitamin A can be found in many processed foods, either limit your intake of vitamin A to less than 5,000 IU daily from supplements or take beta-carotene instead.