Vitamin & Nutrition Corner

Vitamin & Nutrition Corner: Vitamin A

An essential component to ocular health:  Vitamin A

If you ever walk by the vitamin and supplements aisle of the grocery store, you’ll notice dozens of brands specifically promoting eye health.   Which of these vitamins are important to eye health?   How much should you take?    What happens if you get too little or too much of these vitamins?   These are all great questions that I hope to answer with the ‘Vitamin & Nutrition Corner.’

First up is Vitamin A, which is a pivotal nutrient for eye health.   Vitamin A is important in the function of both the exterior and interior portions of the eye.

For example, Vitamin A plays a large role in regulating the make up of your tear or moisture film on the surface of your eye.   Vitamin A is also an antioxidant which reduces oxidative stress on the surface of your eye from environmental conditions and aging.   As a result, a deficiency of vitamin A may lead to dry, irritated eyes.

Vitamin A is also essential for your retina to function properly.  It combines with proteins in your retinal cells that are responsible for absorbing light, especially during night vision.     A lack of Vitamin A would result in diminished or delayed visual ability to adapt during low light conditions, aka night blindness.  Vitamin A also serves as an antioxidant within the retina to reduce chemical stress and it was part of the National Eye Institute’s formula of vitamins used in its landmark study on Macular Degeneration.

No discussion of Vitamin A is complete without talking about Beta-carotene, which is a precursor that is metabolized by your body into vitamin A.   Beta-carotene is found in plants with orange pigments:   carrots, apricots, canteloupe, chili peppers, and sweet potatoes.

When we discuss vitamins, it’s important to note that excessive intake of any vitamin can actually be toxic to your body.   Taking megadoses of vitamins should be avoided until it’s discussed in detail with your primary care physician.    Getting more than 6000 IU of Vitamin A on a daily basis is considered excessive.   Since Vitamin A competes with Vitamin D’s role in bone health, excessive Vitamin A may lead to osteoporosis.  Excessive Vitamin A may also cause fatigue, joint soreness, upset stomach, and irritability.   Smokers should avoid Beta-carotene as it may increase the risk of lung cancer with tobacco use.   Smokers should take vitamin supplements that substitute Lutein in place of Vitamin A.

Yet, consuming proper amounts of Vitamin A or beta-carotene is an important means of keeping your eyes and your body in great health.

How much Vitamin A:

  • The recommended dose is between 1200-5000 IU.

Where to get Vitamin A:

  • Beef and chicken liver are HUGE sources of vitamin A
  • Milk, margarine, and eggs
  • Via Beta-carotene consumption from fresh carrots, canteloupe, etc.
  • Synthetic vitamin supplements

Benefits of Vitamin A:

  • Decreased ocular dryness
  • Better antioxidant protection of the eyes against environmental and aging stress
  • Proper retinal function during night vision
  • Promotion of better macular health in patients with Macular Degeneration
  • Improved bone and teeth development
  • Better skin function, especially during wound healing
  • Improves resistance to respiratory infections
  • Promotes proper testicular and ovarian function