Vitamin C
Ascorbic acid
Vitamins. Modern nutrition.
Also called L-ascorbic acid, Sodium ascorbate, Calcium ascorbate, Ascorbate
Pinyin: wéishēngsù C
Spanish: Vitamina C
High doses cause stones, diarrheaA water-soluble vitamin the body needs to make collagen, heal wounds, and absorb iron from plant foods.
Did you know? In 1747, the Scottish doctor James Lind ran one of the first controlled trials, showing that citrus fruit prevented scurvy. Vitamin C itself was not identified until the 1930s.
What it may help, and how strong the proof is
- Anemia & blood building. Vitamin C eaten in the same meal greatly raises absorption of iron from plant foods such as beans. Several human studies show this. It does not treat anemia on its own.Good proof
- Colds, flu & immunity. Regular vitamin C may shorten colds a little. It does not prevent colds for most people, though trials in people under heavy physical stress, such as marathon runners, found fewer colds.Early proof
- Wounds, burns & bites. Scurvy, from severe vitamin C lack, makes wounds heal poorly. Extra vitamin C helps only people who are low. It has not been shown to speed healing in people who get enough.Early proof
Parts of the body
Traditional use
Inuit and other northern peoples ate raw meat and organ meats, which supply vitamin C and kept scurvy away. Ship crews later relied on citrus fruit for the same reason.
How it is classified
- Herbal actions
- Nutritive, Antioxidant. Energy: neutral.
How people take it
Adults need 90 mg a day (men) or 75 mg a day (women), the RDA. Smokers need 35 mg more a day. The upper limit is 2,000 mg a day from food and pills. Doses near that limit often cause diarrhea and stomach cramps.
Food, juice, tablet and powder.
Where to get it
Good sources are red bell peppers (very rich), kiwi, guava, oranges and orange juice, strawberries, broccoli, Brussels sprouts, kale, and tomatoes. Heat and storage destroy much of it, so raw or lightly cooked food is best. Pills come as ascorbic acid or buffered forms such as sodium ascorbate.
Be careful
Vitamin C is safe at food amounts. High doses can cause diarrhea, cramps and nausea. People with a history of kidney stones, or with iron overload (hemochromatosis), should avoid high doses. Very high doses can throw off some blood sugar meters.
Avoid if: kidney stones; hemochromatosis (iron overload).
Mixing with other things
- Works well together
Vitamin C greatly raises absorption of iron from plant foods, so taking them together helps.
- Works well together
Vitamin C helps recycle vitamin E in the body after vitamin E has done its work.
- Works well together
The body needs vitamin C to build collagen, so the two are often paired.
- Works well together
Vitamin C is needed to turn lysine and proline into collagen.
- Worth knowingDiabetes medicine (metformin, insulin, glipizide, Ozempic)
Very high doses can throw off some blood sugar meter readings.
Found in these formulas
Iron boost (Modern), Cold-season kit (Modern)
The honest take
Vitamin C is essential, and scurvy is real. Most people get enough from food. Extra vitamin C does not prevent colds for most people, and it has not been proven to prevent cancer. Skin and immune claims for high-dose pills are mostly hype.