Your eyes are a remarkable sensory organ. They are also complex and susceptible to numerous problems. Certain nutrients, such as vitamin A, are useful for maintaining the proper function of your eyes. Like all nutritional supplements, vitamin A can have strong effects and may cause harm when used inappropriately; therefore, consult your doctor about the potential use of vitamin A for eye health.
Eyes and Eye Problems
Your eyes work by absorbing light rays that are interpreted by your brain as images. When your eyes function normally, you are able to see clearly, both near and far, in the center of your vision and along the sides. You can also see in bright or dim lighting and are able to detect movement, colors and details. Common eye problems include refractive errors, which require glasses; macular degeneration, a deterioration of central vision; cataract, clouding of the lens; glaucoma, vision loss from fluid pressure in the eye; and conjunctivitis, an infection commonly called pinkeye.
About Vitamin A
Vitamin A is used in your body for gene expression, growth and development, red blood cell production, vision and immunity. The term vitamin A describes related substances, retinoids and carotenoids. Retinyl palmitate, a retinoid, comes from animal foods, such as cod liver oil, eggs, butter and milk. Carotenoids are found in yellow and orange vegetables and fruits, such as sweet potatoes, pumpkins, carrots, squash, cantaloupe and mangoes. Dietary supplements -- capsule and tablets -- commonly contain retinol and beta-carotene forms of vitamin A.
Vision
Vitamin A is used by the retina -- a structure at the back of the eyeball that contains nerve cells. These nerve cells sense light and pass information to the brain that is interpreted as vision. The rod cells within the retina provide peripheral or side vision, detect motion and allow you to see in dim light and at night. Vitamin A, in the form of retinol, is especially important for the rod cells to function normally. Inadequate retinol levels result in a reduced ability to see at night, or night blindness. Vitamin A deficiency can also cause dry eyes, spots in the eye corners and, if severe, blindness.
Immunity
Vitamin A is required for normal functioning of the immune system. Your immune system defends your body against infection, such as conjunctivitis. Retinol helps maintain many of the cells that comprise the immune system.
Caution
While vitamin A can be helpful to maintain eye health, it can also cause harm if used inappropriately. Before taking vitamin supplements, consult a health care professional for personalized advice on vitamin A forms and dosage, as well as for safety considerations. Women who are pregnant or plan to become pregnant should only take vitamin A under a doctor's guidance.
