It does not appear that a person can consume too much beta-carotene, as the body will only convert it into vitamin A as necessary. That said, consuming too much preformed vitamin A can lead to vitamin A toxicity, or hypervitaminosis A.
Symptoms can include :. The use of the topical treatment retinol may also increase vitamin A levels to an unhealthy level. People tend to use retinol as an anti-aging skin cream. Topical products can have adverse effects on the skin, though these will likely be less severe than those resulting from oral overconsumption. However, people should avoid using them during pregnancy. The highest risk of overconsumption is with supplements.
A healthful, balanced diet is unlikely to lead to toxic levels of vitamin A. It should also provide enough vitamin A without needing supplements. Another possible cause of vitamin A toxicity is the use of retinol-based medications. Isotretinoin Accutane is one such example. Doctors sometimes prescribe isotretinoin for severe acne. Anyone using this treatment should avoid taking vitamin A supplements because this drug is a vitamin A derivative.
Learn more about the adverse effects of Accutane here. Vitamin A is an essential nutrient that contributes to many functions in the body, such as protecting eye health.
In the U. Most people can meet their needs for vitamin A through their diet. In some cases, however, a doctor may recommend supplements. How long do vitamins last? Here, learn whether they expire and whether it is safe to take vitamin supplements after their expiration dates.
All vegetables provide key vitamins, minerals, and fiber, but some offer more health benefits than others. Learn about 15 of the most healthful…. Retinol can help reduce the appearance of wrinkles, acne, cellulite, and more. Goldman-Cecil Medicine. National Institutes of Health website.
Vitamin A: fact sheet for health professionals. Updated March 26, Accessed April 30, Ross CA. Vitamin A deficiencies and excess. In: Kliegman RM, St. Nelson Textbook of Pediatrics. Editorial team. Vitamin A. Vitamin A is a fat-soluble vitamin that is stored in the liver. There are two types of vitamin A that are found in the diet. Preformed vitamin A is found in animal products such as meat, fish, poultry, and dairy foods. Precursors to vitamin A, also known as provitamin A, are found in plant-based foods such as fruits and vegetables.
The most common type of pro-vitamin A is beta-carotene. Vitamin A is found in two forms in food: Retinol: Preformed retinol is an active form of vitamin A. It is found in animal liver, whole milk, and some fortified foods. Provitamin A carotenoids: Carotenoids are plant pigments dyes.
For more details, see our health professional fact sheet on Vitamin A. Vitamin A is a fat-soluble vitamin that is naturally present in many foods. Vitamin A is important for normal vision, the immune system , and reproduction. Vitamin A also helps the heart, lungs, kidneys , and other organs work properly.
There are two different types of vitamin A. The first type, preformed vitamin A , is found in meat, poultry, fish, and dairy products. The second type, provitamin A, is found in fruits, vegetables, and other plant-based products.
The most common type of provitamin A in foods and dietary supplements is beta-carotene. The amount of vitamin A you need depends on your age and sex.
Average daily recommended amounts are listed below in micrograms mcg of retinol activity equivalents RAE. Vitamin A is found naturally in many foods and is added to some foods, such as milk and cereal. You can get recommended amounts of vitamin A by eating a variety of foods, including the following:. Vitamin A is available in dietary supplements, usually in the form of retinyl acetate or retinyl palmitate preformed vitamin A , beta-carotene provitamin A , or a combination of preformed and provitamin A.
Most multivitamin-mineral supplements contain vitamin A. Dietary supplements that contain only vitamin A are also available. Most people in the United States get enough vitamin A from the foods they eat, and vitamin A deficiency is rare.
However, certain groups of people are more likely than others to have trouble getting enough vitamin A:. Vitamin A deficiency is rare in the United States, although it is common in many developing countries. The most common symptom of vitamin A deficiency in young children and pregnant women is an eye condition called xerophthalmia. Xerophthalmia is the inability to see in low light, and it can lead to blindness if it isn't treated.
Scientists are studying vitamin A to understand how it affects health. Here are some examples of what this research has shown.
People who eat a lot of foods containing beta-carotene might have a lower risk of certain kinds of cancer, such as lung cancer or prostate cancer. But studies to date have not shown that vitamin A or beta-carotene supplements can help prevent cancer or lower the chances of dying from this disease.
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