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. Once ingested, the body converts these compounds into vitamin A. There are more than known carotenoids. One such carotenoid is beta-carotene. Free radicals are believed to: Contribute to certain long-term diseases Play a role in aging Eating food sources of beta-carotene may reduce the risk for cancer.
Beta-carotene supplements do not seem to reduce cancer risk. Vitamin A is found in both plant and animal foods. Foods with the highest levels of vitamin A include: Beef liver and other organ meats these are high in saturated fat and cholesterol, so limit the amount you eat Some types of fish such as herring and salmon and cod fish oil Eggs Dairy products such as cheese and fortified milk choose non-fat and low-fat dairy options Fortified breakfast cereals Orange and yellow vegetables and fruits, such as carrots, sweet potatoes, mangos, and cantaloupe Broccoli, spinach, and most dark green, leafy vegetables The deeper or brighter the color of a fruit or vegetable, the higher the amount of carotenoids.
Large doses of vitamin A in pregnant women can also cause birth defects. Acute vitamin A poisoning most often occurs when an adult takes several hundred thousand IUs of vitamin A. Chronic vitamin A poisoning may occur in adults who regularly take more than 25, IU a day. Alternative Names. Vitamin A benefit Vitamin A source. Vitamin A Read more. But a few types of fruit provide good amounts, as shown below. You can easily meet your requirements for vitamin A by regularly eating some of the foods listed in this article.
Many foods also contain added vitamin A, including cereals, margarine and dairy products. Since vitamin A is fat-soluble, it is more efficiently absorbed into the bloodstream when eaten with fat. You can improve your absorption of provitamin A from plant sources by adding a dash of oil to your salad.
However, as mentioned above, some people have a genetic mutation that makes the conversion of provitamin A into vitamin A much less efficient 2 , 3. Because of this, vegans should take supplements or make sure to eat plenty of the fruits and vegetables listed above.
Fortunately, foods abundant in vitamin A are usually easy to come by and most are an excellent addition to a healthy diet. This article lists 20 foods that are high in vitamin E. This powerful antioxidant helps protect cells from oxidative stress and is crucial for good…. Healthy hair is a sign of beauty and good overall health.
Here are the top 5 best vitamins to grow your hair, along with 3 other nutrients. Acne surfaces during times of hormonal imbalance. Some seek natural treatments such oral vitamin and mineral supplements. Learn which natural remedies…. Unlike preformed vitamin A, beta-carotene is not known to be teratogenic or lead to reproductive toxicity [ 1 ]. The most significant effect of long-term, excess beta-carotene is carotenodermia, a harmless condition in which the skin becomes yellow-orange [ 1 , 23 ].
This condition can be reversed by discontinuing beta-carotene ingestion. Supplementation with beta-carotene, with or without retinyl palmitate, for 5—8 years has been associated with an increased risk of lung cancer and cardiovascular disease in current and former male and female smokers and in male current and former smokers occupationally exposed to asbestos [ 25 , 39 ]. In the ATBC study, beta-carotene supplements 20 mg daily were also associated with increased mortality, mainly due to lung cancer and ischemic heart disease [ 25 ].
The CARET study ended early, after the investigators found that daily beta-carotene 30 mg and retinyl palmitate 7, mcg RAE [25, IU] supplements increased the risk of lung cancer and cardiovascular disease mortality [ 39 ].
The FNB based these ULs on the amounts associated with an increased risk of liver abnormalities in men and women, teratogenic effects, and a range of toxic effects in infants and children. The FNB also considered levels of preformed vitamin A associated with decreased bone mineral density, but did not use these data as the basis for its ULs because the evidence was conflicting.
The FNB advises against beta-carotene supplements for the general population, except as a provitamin A source to prevent vitamin A deficiency. However, many dietary supplements such as multivitamins do not provide all of their vitamin A as retinol or its ester forms.
For example, the vitamin A in some supplements consists partly or entirely of beta-carotene or other provitamin A carotenoids. In such cases, the percentage of retinol or retinyl ester in the supplement should be used to determine whether an individual's vitamin A intake exceeds the UL. That amount is above the UL for children from birth to 8 years but below the UL for older children and adults.
Vitamin A can interact with certain medications, and some medications can have an adverse effect on vitamin A levels. A few examples are provided below. Individuals taking these and other medications on a regular basis should discuss their vitamin A status with their healthcare providers.
The manufacturers of Alli and Xenical recommend encouraging patients on orlistat to take a multivitamin supplement containing vitamin A and beta-carotene, as well as other fat-soluble vitamins [ 41 , 42 ].
Several synthetic retinoids derived from vitamin A are used orally as prescription medicines. Retinoids can increase the risk of hypervitaminosis A when taken in combination with vitamin A supplements [ 40 ].
The federal government's Dietary Guidelines for Americans notes that "Because foods provide an array of nutrients and other components that have benefits for health, nutritional needs should be met primarily through foods. In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients e. For more information about building a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the U.
Department of Agriculture's MyPlate. This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice. We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.
Updated: March 26, History of changes to this fact sheet. Find ODS on:. Strengthening Knowledge and Understanding of Dietary Supplements. Health Information Health Information. Encyclopedia of Dietary Supplements. London and New York: Informa Healthcare; Ross CA. Vitamin A. Ross A. Vitamin A and Carotenoids. Modern Nutrition in Health and Disease.
Solomons NW. In: Bowman B, Russell R, eds. Present Knowledge in Nutrition. Institute of Medicine. Food and Nutrition Board. Tanumihardjo SA. Vitamin A: biomarkers of nutrition for development.
Food and Drug Administration. Department of Agriculture, Agricultural Research Service. FoodData Central , Dietary supplement use in the United States, J Nutr ; What We Eat in America, World Health Organization. Geneva: World Health Organization; Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis. BMJ ;d Vitamin A deficiency and clinical disease: An historical overview. Vitamin A and preterm infants: what we know, what we don't know, and what we need to know.
Vitamin A supplementation to prevent mortality and short and long-term morbidity in very low birthweight infants. Vitamin A supplementation for postpartum women. Vitamin A supplementation during pregnancy for maternal and newborn outcomes. Elevated vitamin A intake and serum retinol in preadolescent children with cystic fibrosis.
Am J Clin Nutr ; Vitamin A supplementation for cystic fibrosis. Consensus report on nutrition for pediatric patients with cystic fibrosis. J Pediatr Gastroenterol Nutr ; Nutrition management of pediatric patients who have cystic fibrosis. Pediatr Clin North Am ; Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease.
N Engl J Med ; The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. Lack of effect of long-term supplementation with beta carotene on the incidence of malignant neoplasms and cardiovascular disease. The New England journal of medicine ; Dietary supplement use and prostate cancer risk in the Carotene and Retinol Efficacy Trial.
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