Vitamin C (ascorbic acid) is an essential nutrient that supports immune function, promotes healthy skin, and helps protect cells from damage.
As a water-soluble vitamin, extra vitamin C is usually flushed out through urine, making toxicity rare. However, it’s still possible to get too much, especially from supplements.
Vitamin C dissolves in water and isn’t stored in your body. Because of this, vitamin C toxicity is rare. However, large amounts, especially from supplements, can cause side effects. That’s why experts have set an upper limit for how much vitamin C you can safely consume each day.
The tolerable upper intake level (UL) represents the highest daily amount from food and supplements unlikely to cause adverse health effects in most people.
Tolerable Upper Intake Levels (ULs) for Vitamin C in Milligrams (mg)
Age
Male
Female
1-3 years
400 mg
400 mg
4-8 years
650 mg
650 mg
9-13 years
1,200 mg
1,200 mg
14-18 years
1,800 mg
1,800 mg
19+ years
2,000 mg
2,000 mg
No upper limit has been set for infants under one year due to limited data on side effects. At this age, babies should get vitamin C only from breast milk, formula, or food.
The risk of getting too much vitamin C usually comes from supplements, such as high-dose products marketed for immune support.
Some supplements contain 1,000 milligrams or more per serving, making it easy to exceed recommended limits, especially if you take multiple supplements or combine them with a vitamin C–rich diet.
When your intake exceeds what your body can handle, symptoms may appear, including:
- Diarrhea
- Nausea
- Gas or bloating
- Heartburn
- Fatigue
- Headache
- Skin flushing (causing the skin to red or darken)
- Trouble falling or staying asleep
These side effects are often temporary and resolve once you reduce your vitamin C intake.
In people with kidney disease, the body may not be able to remove extra vitamin C as effectively, causing it to build up in the body. This can raise oxalate levels and increase the risk of kidney stones, especially in people with a history of stones or kidney problems.
Vitamin C is a powerful antioxidant that helps protect cells from damage. It also offers several other health benefits, including:
- Immune support: Helps strengthen the immune system and may slightly reduce the length or severity of colds.
- Wound healing: Plays a key role in the body’s ability to repair and maintain tissues.
- Collagen production: Supports the formation of collagen for healthy skin, cartilage, and blood vessels.
- Iron absorption: Improves the absorption of iron from plant-based foods, which can help prevent iron deficiency.
The Recommended Dietary Allowances (RDAs) for vitamin C vary based on age, sex, and life stage. These amounts suggest how much vitamin C most people need each day.
Recommended Dietary Allowances (RDAs) for Vitamin C in Milligrams (mg)
Age
Male
Female
Pregnancy
Breastfeeding
0-6 months*
40 mg
40 mg
7-12 months*
50 mg
50 mg
1-3 years
15 mg
15 mg
4-8 years
25 mg
25 mg
9-13 years
45 mg
45 mg
14-18 years
75 mg
65 mg
80 mg
115 mg
19+
90 mg
75 mg
85 mg
120 mg
*Adequate Intake (AI) is used when an RDA has not been established. This represents the estimated amount thought to meet the needs of people without underlying health conditions.
Most people can meet their vitamin C needs through a balanced diet. Foods rich in vitamin C include:
- Medium orange: 70 milligrams
- Half cup of sliced strawberries: 49 milligrams
- Half cup of raw red bell pepper: 95 milligrams
- Medium kiwi: 64 milligrams
- Half cup of broccoli (cooked): 51 milligrams
Special Considerations
People who smoke need around 35 milligrams more vitamin C each day than people who don’t smoke. This is because research shows that smoking increases oxidative stress and depletes vitamin C levels in the body. Being around secondhand smoke can also lower vitamin C levels, so it’s important to meet at least the daily recommended amount.
People with certain health conditions, such as malabsorption disorders or end-stage kidney disease requiring hemodialysis, may also need higher amounts of vitamin C.
If you are taking vitamin C supplements, check nutrition labels carefully. A healthcare provider or registered dietitian nutritionist (RDN) can help you determine whether your intake is safe and beneficial.
