Vitamin C
An antioxidant that helps with collagen, healing, and iron absorption.
Why it matters
Vitamin C acts as an antioxidant, helps your body make collagen, supports wound healing, and improves absorption of non-heme iron from plant foods. It also supports normal immune function.
- Helps build collagen for skin, blood vessels, cartilage, and bone.
- Supports wound healing and antioxidant defenses.
- Improves absorption of iron from plant-based foods.
If intake is too low
Very low vitamin C intake causes scurvy. Deficiency can lead to fatigue, gum problems, easy bruising, and poor wound healing.
- Fatigue and weakness.
- Swollen or bleeding gums and loose teeth in severe deficiency.
- Poor wound healing, easy bruising, and corkscrew hairs.
If intake is too high
Vitamin C is water-soluble, but very high supplemental doses can still cause problems. Excess intake can trigger diarrhea, nausea, stomach cramps, and raise kidney stone risk in some people.
- Diarrhea, nausea, and abdominal cramping.
- Can increase kidney stone risk in susceptible people.
- Large doses may complicate iron overload disorders.
Adult upper limit: 2,000 mg/day
The adult upper limit is meant to reduce gastrointestinal side effects and other risks from high-dose supplements.
Common food sources
Vitamin C is concentrated in fruits and vegetables, especially fresh produce and fortified juices.
- Citrus fruits, strawberries, kiwi, and tomatoes
- Bell peppers, broccoli, Brussels sprouts, and potatoes
- Fortified juices and some fortified foods
Who may need closer attention
Low intake becomes more likely when produce intake is low or needs are higher than usual.
- Smokers, because smoking increases vitamin C turnover
- People with very limited fruit and vegetable intake
- Anyone with a history of restrictive eating or malabsorption
Use extra caution if
Small details change the risk picture with nutrients more than most people expect.
You have a history of kidney stones or an iron overload condition. High-dose vitamin C is not automatically better just because the nutrient is water-soluble.
Supplement and label notes
Useful context when this nutrient shows up across more than one product.
- High-dose vitamin C is common in powders, drink mixes, chewables, and immune blends.
- Water-soluble does not mean side-effect free; bowel tolerance is often the first limit people hit.
- If you already use a multivitamin, check whether a separate C product is adding a lot more than you intended.
Daily Value targets in SuppMap
These are the same label-style Daily Value targets used in the app.
Official references
These pages were used to draft the summaries on this guide.
Educational only. These pages are not a diagnosis or a substitute for personal medical care.
More guides
Keep moving through the rest of the Daily Value chart from here.