Vitamin A is an antioxidant available in animals’ liver or butter, or in plants that include carotenoids (red and yellow pigments). Carotenoids are responsible for color, they are antioxidants, some their examples are lutein and zeaxanthin.
It is recommended to eat half a carrot a day to provide the body with Vitamin A. Vitamin A is good against night blindness. Uncorrected night blindness can cause xerophthalmia, its symptoms are dryness in the eyes, corneal ulcers and swollen eyelids. Untreated xerophthalmia causes blindness. The lack of this vitamin is a common cause of blindness. It is also prevents cataracts and blindness from macular degeneration, that leads to blindness.
Boys and men who are 11 and older should consume every day 1,000 Retinol Equivalents (RE); girls and women who are 11 and older should consume every day 800 RE. Vitamin A can be measured in International Units (IU): 1 RE = 10 IU for plant products and 1 RE = 3.3 IU for animal products.
People who smoke or drink should consume more vitamin A, because it cannot be absorbed totally because of tobacco and drinking vanishes it from your body. It is recommended to stop using beta-carotene supplements due to their ability to increase smokers' incidence of lung cancer.
Pay attention to the following sources of vitamin A:
| Rich Foods | Food RE (Retinol Equivalents) in 100-gram serving | RE in normal-sized serving | | Cod liver oil | 30,003 | 4,080 (1 tablespoon) | | Liver, beef | 10,503 | 11,868 (4 ounces, 113 grams) | | Liver, chicken | 6,165 | 1,973 (1 liver) | | Carrot | 2,813 | 2,025 (1 carrot) | | Sweet potato | 2,006 | 2,668 (1 sweet potato) | | Kale | 890 | 596 (1 cup, chopped) | | Butternut squash | 780 | 1,092 (1 cup, cubed) | | Red pepper (sweet) | 570 | 849 (1 cup, chopped) | | Mango | 389 | 806 (1 mango) | | Cantaloupe | 322 | 515 (1 cup, cubed) |
Such values are only for raw foods. As a result of cooking they can be decreased, because heat destroys vitamin A and beta-carotene in foods. Thus, it is better to use frozen rather sources than canned ones, because the amount of vitamin A is more in them.
Lutein and Zeaxanthin are also very useful, because they may lessen the risk of developing cataracts and macular degeneration. Lutein and Zeaxanthin are found in green and yellow leafy vegetables and egg yolks. The biggest quantity is spinach. Kale and collard greens have much of them too. Lutein and zeaxanthin are available together in fruits and vegetables, and lutein can become zeaxanthin in your body. They are not produced in our body, that’s why they should be consumed daily. Yellow and orange fruits and vegetables, such as corn contain them too. Cooked vegetables have more lutein than raw, because during cooking the cell walls are broken and the lutein is released.
Vitamin C and Bioflavonoids are required for eyes’ health. A big amount of vitamin C decreases the risk of cataracts, caused by a buildup of protein and leading to cloudy vision. Antioxidant vitamins C and E delay age-related macular degeneration, that cannot be treated. They can also prevent and alleviate glaucoma; they lessen pressure in the eyes of people who suffer from glaucoma. The recommended amount of vitamin C is 60 milligrams (mg) for both men and women. It should be consumed daily, because it cannot be produced in body. It cannot be kept in our body for a long time. People who smoke, drink or have diabetes should consume a bigger amount of vitamin C. It is found in a large amount in citrus fruits, berries, peppers, tropical fruits, potatoes and green, leafy vegetables.
|
