What is Vitamin A?
Vitamin A is another name for a group of fat-soluble compounds highly important for human health. Since vitamin A is fat soluble, it’s stored in body tissue for later use. Most of the vitamin A in your body is kept in your liver in the form of retinyl esters. These esters are then broken down into all-trans-retinol, which binds to retinol binding protein (RBP). It then enters your bloodstream, at which point your body can use it. They’re essential for many processes in your body, including maintaining healthy vision, ensuring the normal function of your immune system and organs and aiding the proper growth and development of babies in the womb.
Vitamin A compounds are found in both animal and plant foods and come in two different forms: preformed vitamin A and provitamin A. Preformed vitamin A is known as the active form of the vitamin, which your body can use just as it is. It’s found in animal products including meat, chicken, fish and dairy and includes the compounds retinol, retinal and retinoic acid. Provitamin A carotenoids — alpha-carotene, beta-carotene and beta-cryptoxanthin — are the inactive form of the vitamin found in plants. These compounds are converted to the active form in your body. For example, beta-carotene is converted to retinol in your small intestine.
What are the benefits of Vitamin A?
1. Preserves Your Eyesight, Prevents Night Blindness and Age-Related Decline!
Vitamin A is essential for preserving your eyesight. This vitamin is needed to convert light that hits your eye into an electrical signal that can be sent to your brain. In fact, one of the first symptoms of vitamin A deficiency can be night blindness, known as nyctalopia. Night blindness occurs in people with vitamin A deficiency, as the vitamin is a major component of the pigment rhodopsin. Rhodopsin is found in the retina of your eye and extremely sensitive to light. People with this condition can still see normally during the day, but have reduced vision in darkness as their eyes struggle to pick up light at lower levels. In addition to preventing night blindness, eating adequate amounts of beta-carotene may help slow the decline in eyesight that some people experience as they age. Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. Though its exact cause is unknown, it’s thought to be the result of cellular damage to the retina, attributable to oxidative stress.
2. May Lower Your Risk of Different Types of Cancers
Cancer occurs when abnormal cells begin to grow or divide in an uncontrolled way. As vitamin A plays an important role in the growth and development of your cells, its influence on cancer risk and role in cancer prevention is of interest to scientists. In observational studies, eating higher amounts of vitamin A in the form of beta-carotene has been linked to a decreased risk of certain types of cancer, including Hodgkin’s lymphoma, as well as cervical, lung and bladder cancer.
Yet, though high intakes of vitamin A from plant foods have been associated with a reduced risk of cancer, animal foods which contain active forms of vitamin A aren’t linked in the same way (14Trusted Source, 15Trusted Source).
Similarly, vitamin A supplements haven’t shown the same beneficial effects (16Trusted Source).
In fact, in some studies, smokers taking beta-carotene supplements experienced an increased risk of lung cancer (17Trusted Source, 18Trusted Source, 19Trusted Source).
At the moment, the relationship between vitamin A levels in your body and cancer risk is still not fully understood.
Still, current evidence suggests that getting adequate vitamin A, especially from plants, is important for healthy cell division and may reduce your risk of some types of cancer.