Research, evidence, and sources
What this page is for
Wound healing in a fact sheet is not the same thing as a change you can see in the mirror.
What the reviewed sources say
“The body also needs vitamin C to make collagen, a protein required to help wounds heal.”
Vitamin C, also called ascorbic acid, is an antioxidant. It helps protect cells from free radicals, which form when the body turns food into energy and which also come from cigarette smoke, air pollution, and ultraviolet light from the sun. The body needs vitamin C to make collagen, a protein required to help wounds heal.
People who get very little vitamin C, below about 10 milligrams a day for many weeks, can develop scurvy. Scurvy can include fatigue, spots on the skin, joint pain, poor wound healing, and corkscrew hairs. The fact sheet says deficiency is rare in the United States and Canada. Those skin findings are deficiency signs. They are not evidence that a vitamin C supplement changes the look of healthy skin.
Most multivitamins contain vitamin C, and it is also sold alone. The form is usually ascorbic acid. Other forms include mineral ascorbates and ascorbic acid with bioflavonoids. Research has not shown that any form is better than the others. The adult upper limit is 2,000 milligrams a day from food and supplements together. Too much can cause diarrhea, nausea, and stomach cramps. People with hemochromatosis can be harmed by high doses because vitamin C increases iron absorption.
Vitamin C — Consumer Fact Sheet NIH Office of Dietary Supplements. Updated 2021-03-22. Retrieved 2026-10-07.
How to compare a label
“The nutrition label for a dietary supplement is called a “Supplement Facts” panel.”
Start with the Supplement Facts panel. The FDA’s labeling guide uses that name for a dietary supplement’s nutrition label.
Read the ingredient name, the amount per serving, and the serving size. A blend that lists several ingredients is a different product from a bottle that is only one of them. The price on a retailer card is the package price, not a price per serving, and a sale ribbon is not a checked comparison price.
- Dosage unit converterConvert grams, milligrams, and micrograms. IU converts only when the vitamin form is known.
- Price per servingSee what one serving costs from the container price and the servings on the label.
- Cost per labeled amountSee what a labeled amount of an ingredient costs. A second product is optional.
- Daily nutrient targetsPublished folate, magnesium, and vitamin A figures for a life stage.
Dietary Supplement Labeling Guide: Chapter IV. Nutrition Labeling U.S. Food and Drug Administration. Retrieved 2026-10-05.
Sources
- Vitamin C — Consumer Fact Sheet NIH Office of Dietary Supplements. Updated 2021-03-22. Retrieved 2026-10-07.
- Dietary Supplement Labeling Guide: Chapter IV. Nutrition Labeling U.S. Food and Drug Administration. Retrieved 2026-10-05.
