Lutein is a carotenoid found in several natural sources, including green vegetables like spinach or collard greens, in egg yolks, and in some fruits. This carotenoid is a strong antioxidant, which generally refers to a molecule that helps to protect an organism from free radical damage. Lutein in particular has an established effect in protecting eye health. Lutein vitamins refer to dietary supplements that contain high levels of lutein.
The important role of lutein in eye health can be demonstrated by the fact that people are born with lutein in the tissues of their eyes. The body does not produce lutein, so lutein in the eye cannot be replaced naturally and must be obtained from the diet. Ingested lutein is circulated throughout the body and a large proportion of this compound is stored in the eye tissues. Many scientific studies support the notion that ingesting high levels of lutein vitamins help protect the eye from disease, most specifically age-related macular degeneration and cataracts.
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Lutein protects the eye tissue by acting as a filter for ultraviolet light rays that are damaging to certain areas of the eye, like the macula. This compound appears to filter out the blue light of the visible spectrum. In addition to absorbing light, lutein also has antioxidant functions and can protect the eye tissue from oxidative damage.
Although lutein mainly accumulates in eye tissues, lutein vitamins may also have other beneficial effects throughout the body. Like many antioxidants, lutein may help prevent certain types of cancer by preventing free radical damage to tissues. Lutein vitamins may also help prevent cardiovascular disease.
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It is thought that the majority of Americans do not get enough lutein from the diet, and for this reason, many health professionals recommend supplementation with lutein vitamins. Lutein vitamins may be sold as lutein alone, although it is often packaged into a supplement with other antioxidants. Zeaxanthin is a carotenoid that is very similar to lutein functionally, and these two antioxidants are often combined together and sold as eye health supplements. Alternatively, these carotenoids may be combined with A vitamins. Most of the lutein in supplements is derived from marigold flowers, a rich source of lutein.
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Little has been reported regarding negative side effects of lutein vitamins. This carotenoid is fat soluble, which means that excess levels are stored in fat and are not excreted in urine like water-soluble vitamins. Caution should always be exerted when supplementing with a fat-soluble substance. An advantage of lutein is that it is different from many other carotenoids because it is not converted into active vitamin A forms in the body, making it less toxic than these substances at high levels. Most health professionals recommend supplementing with lutein at levels close to what one would obtain from a healthy diet, which is approximately 3 mg per day.