Vitamin A
Retinol and beta-carotene
Vitamins. Modern nutrition.
Also called Retinol, Beta-carotene, Retinyl palmitate, Provitamin A
Pinyin: wéishēngsù A
Spanish: Vitamina A
High doses harm liver, babiesA fat-soluble vitamin the body needs for night vision, a strong immune system, and healthy skin and gut lining.
Did you know? Vitamin A was one of the first two vitamins ever named, in 1913, when scientists called it 'fat-soluble A'.
What it may help, and how strong the proof is
- Eyes & vision. Vitamin A is needed to make rhodopsin, the pigment that lets the eye see in dim light. Low vitamin A causes night blindness, and severe lack can damage the eye. Fixing a deficiency restores these signs, but extra vitamin A does not improve sight in people who get enough.Strong proof
- Colds, flu & immunity. Large trials in children with low vitamin A found fewer deaths overall. That does not show that extra vitamin A boosts immunity in people who already get enough.Early proof
Parts of the body
Traditional use
Cod liver oil, which is rich in vitamin A, was given to children in Europe and North America in the 1800s and early 1900s to support growth. Liver and fish were common in many traditional diets for the same reason.
How it is classified
- Herbal actions
- Nutritive, Immune balancer. Energy: neutral.
How people take it
Adults need 900 mcg RAE a day (men) or 700 mcg RAE a day (women). RAE means retinol activity equivalents, a way to count animal and plant forms together. The upper limit is 3,000 mcg RAE a day for preformed vitamin A from food and pills. Beta-carotene from plants has no set upper limit, but high beta-carotene pills are not advised.
Food, capsule and oil.
Where to get it
Best food sources are beef liver (very rich, so eat it rarely), sweet potato, carrots, cooked spinach and kale, butternut squash, cantaloupe, mango, eggs, and fortified milk. Pills come as retinyl palmitate (preformed vitamin A) or beta-carotene (from plants), often in multivitamins.
Be careful
Too much preformed vitamin A can cause headache, dry skin, bone pain, and liver damage. Pregnant women should not exceed 3,000 mcg a day, because higher doses can cause birth defects. Smokers should avoid beta-carotene pills, which raised lung cancer risk in two large trials.
Avoid if: pregnancy (high doses); liver disease; smokers (beta-carotene pills); heavy drinking.
Mixing with other things
- Works well together
Both are fat-soluble and help protect cells from damage.
- Works well together
Zinc helps the body move stored vitamin A from the liver into the blood.
- Use cautionAlcohol (beer, wine, spirits)
Heavy drinking and extra preformed vitamin A both stress the liver.
The honest take
Vitamin A is essential, and deficiency is a leading cause of preventable blindness in children in poor countries. For most people who eat a varied diet, pills add little. Beta-carotene pills can raise lung cancer risk in smokers.