Vitamins A, C, and E are essential for maintaining good eye health. B vitamins and other nutrients can also be good for the eyes.
Deficiencies in particular vitamins can increase the risk of some eye conditions, such as cataracts, glaucoma, and age-related macular degeneration. Research suggests that some vitamin and mineral supplements may help protect against or slow the development of these conditions.
This article outlines the vitamins and minerals essential for good eye health and how people can add them to their diet.
Vitamin A and beta carotene
Vitamin A is essential for good vision. It is a component of the protein rhodopsin, which allows the eye to see in low-light conditions. According to the American Academy of Ophthalmology, a deficiency in vitamin A can lead to night blindness.
Vitamin A also supports the function of the cornea, which is the protective outer layer of the eye. A person who is deficient in vitamin A may find that their eyes produce too little moisture to stay lubricated.
Beta carotene is the primary source of vitamin A in the human diet. Beta carotene is a type of plant pigment called a carotenoid that exists in many colorful fruits and vegetables. When a person consumes carotenoids, their body converts the pigments into vitamin A.
Foods for vitamin A
People can add vitamin A into their diet by eating the following foods:
- sweet potato
- red pepper
Alpha tocopherol is a form of vitamin E that has particularly powerful antioxidant properties.
Antioxidants help fight free radicals, which damage tissues throughout the body. Sometimes, free radicals may damage proteins within the eye. This damage can result in the development of cloudy areas — cataracts — on the lens of the eye.
A 2015 meta-analyses concluded that a high intake of vitamin E, whether through the diet or supplementation, may reduce the risk of developing cataracts.
Foods for vitamin E
Foods high in vitamin E include:
- sunflower seeds
- safflower oil
- soybean, corn, and wheat germ oil
Vitamin C plays an important role in the eye itself, protecting against UV light damage. While the concentration of vitamin C in the eyes lessens with age, diet and supplementation can counteract this.
Vitamin C also helps protect against oxidative damage. Oxidative damage is a key factor in two of the most common age-related cataracts: cortical and nuclear cataracts. Cortical cataracts develop on the edges of the lens, while nuclear cataracts occur deep in their center.
A 10-year longitudinal study investigated different factors that may help prevent nuclear cataract development. The study involved more than 1,000 pairs of female twins. At the end of the study period, participants who consumed more vitamin C showed a 33% reduction in the risk of cataract progression. They also had clearer lenses overall.
However, a 2020 review concluded that more research is necessary to fully identify the role of vitamin C as an anticataract therapy.
Foods for vitamin C
The following foods contain high levels of vitamin C:
- oranges and orange juice
- Brussels sprouts
- grapefruit juice
A 2015 review found that people with tend to have lower blood B12 levels. However, researchers noted insufficient evidence to confirm a direct link.
However, this particular study only included women. Further research is, therefore, necessary to support the use of B-vitamins in preventing AMD in both males and females.
A 2018 nationwide study in South Korea found a link between a reduced intake of vitamin B3 (niacin) and glaucoma. In people with glaucoma, a buildup of fluid within the eye puts pressure on the optic nerve. Over time, this can damage the nerve, resulting in vision loss.
A small 2020 study also found that supplementation of vitamin B1 and mecobalamin may reduce symptoms of dry eye disease.
Foods for B vitamins
The following foods contain high levels of various B vitamins:
B Vitamin Foods
Vitamin B1 (thiamine): beans, lentils, pork, fish, green peas, yogurt
Vitamin B2 (riboflavin): beef, oats, yogurt, milk, clams, mushrooms, almonds
Vitamin B3 (niacin): beef liver, chicken, salmon and tuna, brown and white rice, peanuts
Vitamin B6 (pyridoxine): chickpeas, dark leafy greens, poultry, beef liver, salmon, and tuna
Vitamin B9 (folic acid): dark leafy greens, peanuts, beans, seafood, sunflower seeds, eggs
Vitamin B12 (cobalamin): fish, liver, red meat, poultry, eggs
Other nutrients for eye health
Research suggests that the following nutrients are also beneficial for the eyes.
Omega-3 fatty acids
The retina of the eye contains a high concentration of omega-3 fatty acids. These fatty acids help protect the retina from damage and degeneration. Small animal studies have found that omega-3 supplementation can slow age-related retina degradation. However, further human studies are necessary to fully assess the link.
Many doctors recommend omega-3 fatty acids for the treatment of dry eye syndrome. A person with dry eye syndrome does not produce enough tears to keep the eyes lubricated. Certain omega-3 supplements have been approved by Health Canada for dry eyes. Omega-3 fatty acids are best delivered the re-esterified triglyceride form (rTG), which allows for easier absorption into the bloodstream. However, a large randomized control study found no significant improvement in dry eye symptoms when compared to a placebo.
Foods rich in omega-3 fatty acids include:
- oily fish, such as sardines, tuna, and herring
- chia seeds
Lutein and zeaxanthin
Lutein and zeaxanthin are carotenoids that exist in high quantities in green leafy vegetables. They are also present in the lens and retina of the eye.
As antioxidants, lutein and zeaxanthin may help reduce oxidative damage in the retina. Research in 2017 suggests that taking approximately 6 milligrams (mg) per day of lutein and zeaxanthin may lower a person’s risk of developing AMD. An intake of 0.5–1 mg per day may also lower the risk of glaucoma.
Sources of lutein and zeaxanthin include:
- egg yolks
Zinc is a mineral that helps maintain the health of the retina, cell membranes, and protein structure of the eye.
Zinc allows vitamin A to travel from the liver to the retina to produce melanin. Melanin is a pigment that protects the eyes from UV light.
Zinc supplementation may help people who have AMD or are at risk of developing the condition. According to the American Optometric Association, taking 40–80 mg of zinc each day, alongside certain antioxidants, could slow the progression of advanced AMD by 25%. It could also reduce visual acuity loss by 19%.
Sources of zinc include:
- seafood, such as oysters, crab, and lobster
- pumpkin seeds
- whole grains
- fortified cereals
Vitamins and the diet
A healthy, balanced diet can help promote good eye health and protect a person’s vision. A varied diet rich in nutritionally-dense foods can often provide adequate amounts of all vitamins and minerals.
However, some people may require additional supplementation to reach certain nutritional targets if their diet cannot provide this.
In some cases, taking supplements may lead to side effects, so it is important for people to speak with a doctor before making large dietary changes. For example, high dosages of zinc can affect how the body absorbs copper.
Specific vitamins and nutrients are essential for maintaining good eye health. Some may even help prevent certain eye diseases from developing or progressing.
A healthy, balanced diet will provide people with the necessary range of nutrients. The diet should include whole grains, legumes, and plenty of colorful fruits and vegetables.
Your Local Optometrist
Regular checkups with an eye doctor are very important because a professional eye exam will determine what type of care your eyes need and whether or not your vision is healthy. If you’re looking for an optometrist in the Toronto area, contact Tonic Eye Care today for all of your vision needs!