Vitaminn A possibly is the most important vitamin for the health of your eyes. This vitamin keeps your vision working and the small organelles of your eyes working properly, the cornea included. There are dietary recommendations concerning vitamin A that you should meet. If you do not, the health of your eyes and your vision may be compromised.
Vitamin A
Vitamin A is an umbrella term for a variety of compounds known as retinols and retanoids. The different versions of vitamin A are ingested and converted to the form the body needs them to be. Vitamin A is responsible for many different functions, including eye health, cellular reproduction and gene expression, fetal growth and red blood cell production. Vitamin A promotes good vision by keeping the retina and the cornea of the eye healthy.
The Cornea: Function
The cornea of your eye is the clear, transparent area that sits on top of the entire front of your eye. It lies over the iris, pupil and lens. It's job is to allow light to pass through the eye. The light that goes through the eye transmits to the back of the eye, your retina. The amount of light that passes through the eye allows the brain to distinguish what the eye sees.
Vitamin A and The Cornea
A vitamin A deficiency can negatively affect the health of your cornea. A condition known as xerophthalmia, or dry eye syndrome, can occur. A vitamin A deficiency causes your eyes to produce less tears. When your eyes become dry, there is less lubrication for your cornea. This can lead to a cloudy cornea and may impair your vision.
Vitamin A Recommendations and Sources
A vitamin A deficiency is quite rare in the United States, according to the PubMed website. Vitamin A is a fat soluble vitamins, which means that any excess vitamin A that is consumed is stored. So even if you lack vitamin A in your diet for a day or so, your body probably has enough stored up to last. Adult males need to consume 900 mcg of vitamin A each day and adult females need 700 mcg per day. Sources of vitamin A include dairy and meat products brightly colored vegetables and fruits provide beta-carotene, a substance that your body can convert to vitamin A.
References
- "Nutrition: Concepts and Controversies"; Frances Sizer and Eleanor Whitney; 2004.
- Linus Pauling Institute: Vitamin A; Jane Higdon, PhD; 2005
- "Anatomy and Physiology"; Kenneth S. Saladin; 2004
- PubMed Health: Dry Eye Syndrome; Daniel E. Bustos, MD, MS; November 2010
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