MORE NUTRIENTS FOR YOUR EYES
We’re so often hounded to eat more fruits and vegetables to help protect us against everything from heart disease to cancer to digestive disease. But what many people don’t realize is the vitamins and minerals found in those foods – specifically vitamins A, C and E, riboflavin, beta-carotene and zinc – are also good for our eyes.
These nutrients work individually and together to help us maintain normal vision throughout our lives. They also help us protect our eyes from the harmful effects of the environment and, as we age, from the development and progression of age-related eye disease.
What is Vitamin A?
Vitamin A is a fat-soluble vitamin that is contributes to the maintenance of normal vision and maintenance of a normal immune system. There are two different types of vitamin A, preformed vitamin A and provitamin A.
Vitamin A in the Diet
Preformed vitamin A, is found in meat, poultry, fish, and dairy products. Provitamin A is found in fruits, vegetables, and other plant-based foods. The most common type of provitamin A is beta-carotene.
Vitamin A in the Eye
Vitamin A is an essential component of a protein that absorbs light in the eye called rhodopsin. It also supports the normal functioning of the cornea.
What is Vitamin C?
Vitamin C is a water-soluble vitamin and a powerful antioxidant that is found in many fruits and vegetables. Most people think of it has the vitamin that makes oranges and orange juice so good for you.
Vitamin C in the Diet
Vitamin C is available in many fruits and vegetables – many of which have more vitamin C than an orange. Besides other citrus fruits, vitamin C can also be found in strawberries, peppers, papaya, pineapple, brussel sprouts and broccoli. The Average Requirement (AR) for vitamin C, according to the European Food Safety Authority (EFSA), is 110 mg/day for men, 95 mg/day for women and an additional 10 mg/day for pregnant women and an additional 60 mg/day for lactating women.
Vitamin C and Your Eyes
Vitamin C acts in three different ways within the eyes to protect them:
- As an antioxidant
- As a stimulus for regenerating vitamin E
- To maintain collagen synthesis
Antioxidant: While we all enjoy a sunny day, it produces high energy UV light (also known as blue light) that can damage our eyes. That blue light can interact with oxygen to create something called “free radicals.” Those free radicals can cause a series of reactions in the eye that ultimately result in the formation of the same kind of age spots that older adults get on their skin.
Vitamin E regeneration: Although vitamin E is itself an antioxidant, it can also get oxidized through various processes in the body. Vitamin C helps regenerate vitamin E when that occurs.
Collagen synthesis: Vitamin C helps the body to make and maintain this connective tissue throughout our bodies, including the collagen that is found in the cornea of the eye.
What is Vitamin E?
Vitamin E is a fat-soluble vitamin that acts as an antioxidant within our cell membranes.
Vitamin E in the Diet
As a fat-soluble vitamin, vitamin E is primarily found in the oils of nuts, seeds, legumes as well as vegetable oils and avocado. EFSA has not established an average requirement for vitamin E but has set an upper limit of 300 mg/day for adults.
Vitamin E in the Eye
Vitamin E is an antioxidant that works primarily in the cell membranes, where fats are stored and help maintain the cell walls. This is particularly important in the retina of the eye, which is highly concentrated with fatty acids, like EPA and DHA.
What is Riboflavin?
Riboflavin, which is also known as vitamin B2, is a water-soluble vitamin that plays an important role in energy production and metabolism of fats, carbohydrates, and proteins. It also assists in the actions of enzymes.
Riboflavin in the Diet
Riboflavin is found in dairy products, eggs, dark green leafy vegetables, lean meats, legumes, milk, nuts and fortified breads and cereals. The recommended dietary allowance for riboflavin is 1.4 mg/day.
Riboflavin in the Eye
Riboflavin contributes to the maintenance of normal vision. It helps important antioxidants in the eye work against free radicals.
What is Beta-Carotene?
If you ever wondered why carrots are supposed to be so good for your eye health, the answer is beta-carotene. Beta-carotene is what gives carrots and other fruits and vegetables their orange color.
Beta-Carotene in the Diet
There are many other great-tasting foods besides carrots that contain beta-carotene. Besides the orange and reddish orange foods like sweet potatoes, red pepper, winter squash and others, beta-carotene is also found in dark, green leafy vegetables like spinach and kale. Because beta-carotene is not a vitamin but a precursor to one (see below), there is no dietary recommendation.
Beta-Carotene in the Eye
Beta-carotene is a form of vitamin A that is only found in plants called provitamin A. Vitamin A contributes to the maintenance of normal vision. It does so by protecting the surface of the cornea, helping vision in dim light and supporting immune function. Beta-carotene also acts as an antioxidant.
What is Zinc?
Zinc is a mineral that is found in many human enzymes. Enzymes act as catalysts for various processes that take place within the body.
Zinc in the Diet
Zinc is found in animal products like shellfish, milk, cheese, chicken and turkey but also in plant foods like nuts and cereals. EFSA has set the average requirement for zinc as 7.5 mg/day for men and 5.5 mg/day for women.
Zinc in the Eye
Zinc contributes to normal metabolism of vitamin A. It also supports the structure of proteins and cell membranes, including those in the eye. Zinc also helps nerve cells to send signals to one another. Zinc contributes to the maintenance of normal vision.