Vitamin C (ascorbic acid)
Water-soluble vitamin for connective tissue, wound healing and iron absorption
Also known as
Definition
Vitamin C (ascorbic acid) is a water-soluble vitamin that the body cannot make and can store only in small amounts. It needs it to form collagen for skin, tendons, ligaments and blood vessels, for wound healing, for cartilage, bones and teeth, and for absorbing iron. Vitamin C is also one of the antioxidants. Excess amounts leave the body in the urine, so a regular intake from fruit and vegetables is needed.
| Parameter | Value |
|---|---|
| Unit | varies by lab and method |
| Reference Range | No uniform reference range in this glossary: labs measure vitamin C with different methods and set their own ranges. The reference range on your own report is what counts; discuss it with your doctor. |
Agree on your personal target range with your doctor.
↓ What a low value means
Too little vitamin C can come with bleeding and inflamed gums, easy bruising, nosebleeds, slow wound healing, reduced ability to fight infection, rough, dry, scaly skin, dry hair, swollen and painful joints and anemia. The severe form is called scurvy and mainly affects older, malnourished adults. Smoking and secondhand smoke raise the need for vitamin C, as do pregnancy and breastfeeding. Discuss a low result with your doctor.
↑ What a high value means
A high value can reflect a high recent intake, for example from supplements. Serious side effects are rare, because the body stores very little vitamin C and excretes the excess. Very large amounts from supplements can, however, cause stomach upset, diarrhea and, rarely, kidney stones. Large amounts are not recommended during pregnancy, because they can lead to vitamin C deficiency in the baby after delivery. Discuss any deviation with your doctor.
When to test
A test is mainly considered when symptoms suggest a deficiency, such as bleeding gums, easy bruising or poorly healing wounds, or with a very one-sided diet low in fruit and vegetables. Because the body stores very little vitamin C, your recent intake can affect the result. Mention supplements before the blood draw and check the preparation with your practice.
Frequently asked questions
Does the body store vitamin C? +
Only to a small extent. Vitamin C is water-soluble, and excess amounts leave the body in the urine. That is why a regular intake is needed, and a single blood value can depend on how much vitamin C you have taken in recently.
What does vitamin C have to do with iron? +
Vitamin C helps the body absorb iron. A vitamin C deficiency can therefore also come with anemia. If your iron or blood values are abnormal, your doctor will assess what role your diet plays.
Can too much vitamin C be harmful? +
Serious side effects are rare. Very large amounts from supplements can, however, cause stomach upset, diarrhea and, rarely, kidney stones. Large amounts are not recommended during pregnancy.
Which foods are rich in vitamin C? +
All fruits and vegetables contain some vitamin C; particularly rich sources include citrus fruits, kiwi, mango, papaya, pineapple, berries, peppers, broccoli, Brussels sprouts, cauliflower, leafy greens and tomatoes. Cooking, long storage and light can reduce the content; raw foods contain the most.
Vitamin C (ascorbic acid)
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.