Vitamin A is an essential vitamin that is needed for a variety of important metabolic process in the body. For this reason a deficiency can result in a variety of different disorders such as immune system problems, poor skin health and night blindness among others. As an antioxidant vitamin A also protects our cells from oxidative damage.
Dietary vitamin A is found in both animal products and plant form. Animal products contain actual vitamin A (called retinol) while plant sources, especially specific vegetables, contain carotenoids that can be transformed by the liver into vitamin A. There are more than 600 known carotenoids found in plants, but only 4 of them can be turned into vitamin A: beta-carotene, alpha-carotene, gamma-carotene and beta-cryptoxanthin. So these carotenes are also commonly referred to as ‘pro-vitamin A’. To learn more about carotenoids visit what are carotenoids?
Eye health Benefits of Vitamin A
“Eating carrots helps you see in the dark” is an age old belief that is now grounded in solid science. Carrots are abundant in pro-vitamin A carotenoids and vitamin A is essential for seeing in the dark. In fact vitamin A is essential for seeing, period! In the case of our eyes vitamin A is metabolized one step further into another chemical called rhodopsin. Rhodopsin is purple based plant pigment that absorbs light waves and is essential for the eye to see the colors black and white and therefore make sense of its environment in low light. So without rhodopsin we become night blind. Although now a rare condition in more affluent countries, night blindness can still effect people in impoverished regions where they have little access to vitamin A rich vegetables and meat.
Vitamin A benefits for Skin Health and Organs
An adequate supply of vitamin A in our diet is essential for the health and well being of our skin. Vitamin A is needed to create epithelial skin, the outer layer of the skin that we see and is exposed to the environment. Even a slightly inadequate intake of vitamin A can result in a dry flaky appearance of the skin. Also a powerful antioxidant, vitamin A can also protect the epithelial skin cells from harmful toxins in the environment.
Vitamin A is also needed in the creation and maintenance of internal skin structures called epithelium. Epithelium is important for protecting our organs and is necessary for other functions. Epithelium cells in the small intestine are needed for absorbing nutrients from the food we eat. Epithelial cells in the kidney excrete waste products from the body while epithelial cells in the lungs help to remove dust particles and foreign bodies that we breathe in.
Vitamin A and the Immune System
Along with vitamin C and vitamin E, vitamin A is essential to the proper functioning of the immune system. Vitamin A enhances the functioning of certain white blood cells, improves the receptivity of antibodies to antigens and fights off viral infections.
Vitamin A food Sources
Animal: animal livers are one of the best sources of vitamin A because the liver is where carotenoids from plant foods are converted to vitamin A. Eggs, milk, cheese and butter are also good sources.
Plant: pro-vitamin A carotenoids are found abundantly in carrots, pumpkins, squash, kale, spinach and other leafy greens. It is important to note that carotenoids in plant sources are digested considerably more effectively by cooking or other processing methods like juicing. So carrot juice or steamed carrots are therefore a considerably better source of carotenoids than eating raw carrots. Because vitamin A is also a fat soluble vitamin, its digestion is also greatly improved by eating it along with fats or oils. Adding olive oil or avocados to vegetable salads has been shown to greatly enhance carotenoid digestion and absorption into the blood stream.