Vitamins play an role in the health of many tissues and functions in your body, including vision. If you do not get enough of vitamin A, you may develop vision problems that can ultimately lead to blindness. Vitamin A related blindness is uncommon in developed countries such as the United States. Talk to your doctor before taking any sort of vitamin supplement.
What Is Vitamin A?
Vitamin A is a term that refers to many different compounds that are related, such as retinol and retinal. Vitamin A is not naturally found in most foods, but many different plants contain substances, known as carotenoids, that can be converted into vitamin A by your intestines. Only 10 percent of the carotenoids in plants can be turned into vitamin A; one of the best known ones is beta carotene. This substance can be found in yellow, orange and green plants. Animal-based foods also contain retinyl palmitate, another substance that can be turned into vitamin A.
Vitamin A and Vision
Vitamin A is important for vision because it is needed to form the pigment rhodopsin. The retina is the part of the eye that is responsible for converting light rays into neurological signals that can be converted into images. Cells in the retina, known as the rods and cones, need rhodopsin in order to absorb light rays. Rhodopsin is important for all kinds of vision, including "night vision," which allows you to see in low light conditions.
Vitamin A Deficiency and Vision Problems
A lack of vitamin A can impair your body's ability to make rhodopsin, resulting in vision problems. In children, a vitamin A deficiency is the leading cause of preventable blindness and is typically due to malnutrition. Vitamin A deficiencies can also affect the vision of adults. A mild deficiency can make it hard for you to see in low light conditions and can also cause small changes in the whites of your eyes. A severe deficiency results in your eyes becoming dry, which can ultimately cause scarring of the eye that can lead to blindness.
Vitamin A Overdose
Vitamin A deficiencies are uncommon in developed countries. If you are concerned that you are not getting enough vitamin A, talk to your doctor. Although vitamin A is important for your health, getting too much vitamin A from supplements can be dangerous and cause blurred vision, bone pain, dizziness, increased pressure in your head and liver problems. Be sure to talk to your doctor before taking any sort of vitamin supplement.