Vitamin a (Retinoid)
Vitamin A is key for good vision, a healthy immune system, and cell growth. There are two types of vitamin A. This entry is primarily about the active form of vitamin A -- retinoids -- that comes from animal products. Beta-carotene is among the second type of vitamin A, which comes from plants.
The American Heart Association recommends obtaining antioxidants, including beta-carotene, by eating a well-balanced diet high in fruits, vegetables, and whole grains rather than from supplements until more is known about the risks and benefits of supplementation.
High doses of antioxidants (including vitamin A) may actually do more harm than good. Vitamin A supplementation alone, or in combination with other antioxidants, is associated with an increased risk of mortality from all causes, according to an analysis of multiple studies.
Why do people take vitamin A?
Topical and oral retinoids are common prescription treatments for acne and other skin conditions, including wrinkles. Oral vitamin A is also used as a treatment for measles and dry eye in people with low levels of vitamin A. Vitamin A is also used for a specific type of leukemia.
Vitamin A has been studied as a treatment for many other conditions, including cancers, cataracts, and HIV. However, the results are inconclusive.
Most people get enough vitamin A from their diets. However, a doctor might suggest vitamin A supplements to people who have vitamin A deficiencies. People most likely to have vitamin A deficiency are those with diseases (such as digestive disorders) or very poor diets.
How much vitamin A should you take?
The recommended dietary allowance (RDA) includes the vitamin A you get from both the food you eat and any supplements you take.
Category
Vitamin A: Recommended Dietary Allowance (RDA) in micrograms (mcg) of Retinol Activity Equivalents (RAE)
CHILDREN
1-3 years
300 mcg/day
4-8 years
400 mcg/day
9-13 years
600 mcg/day
FEMALES
14 years and up
700 mcg/day
Pregnant
14-18 years: 750 mcg/day 19 years and over: 770 mcg/day
Breastfeeding
Under 19 years: 1,200 mcg/day
19 years and over: 1,300 mcg/day
MALES
14 years and up
900 mcg/day
The tolerable upper intake levels of a supplement are the highest amount that most people can take safely. Higher doses might be used to treat vitamin A deficiencies. But you should never take more unless a doctor says so.
Category (Children & Adults)
Tolerable Upper Intake Levels (UL) of Retinol* in micrograms (mcg) of Retinol Activity Equivalents (RAE)
0-3 years
600 mcg/day
4-8 years
900 mcg/day
9-13 years
1,700 mcg/day
14-18 years
2,800 mcg/day
19 years and up
3,000 mcg/day
* There is no upper limit for vitamin A from beta-carotene.
Can you get vitamin A naturally from foods?
Getting enough vitamin A can easily be obtained through a healthy diet.
Good food sources of retinoid vitamin A include:
- Eggs
- Whole milk
- Liver
- Fortified skim milk and cereals
Plant sources of vitamin A (from beta-carotene) include sweet potatoes, carrots, spinach, and apricots.
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