All About Vitamin C: Benefits, Sources, Risks, and More

Medically Reviewed By Imashi Fernando, MS, RDN
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Vitamin C is an essential nutrient with antioxidant properties. It is present in fresh fruits and vegetables. Vitamin C, or ascorbic acid, is a water soluble vitamin that supports the immune system to prevent infections and fight diseases. Our bodies do not store vitamin C, so we should source this nutrient by consuming fruits and vegetables every day.

This article explains the benefits of vitamin C and details how to include vitamin C in your diet. It also expands on the recommended dosages and what might happen if you exceed or do not meet this amount.

What are the benefits of vitamin C?

there are rows of orange slice, which are high in vitamin c
ZHPH Production/Stocksy United

Vitamin C is essential for disease prevention, immune system functionality, and connective tissue and blood vessel health. As an antioxidant, it protects the body from damage due to free radical exposure, including air pollution, UV light, and cigarette smoke.  

The body uses vitamin C to promote the production of collagen, which is a vital protein necessary for building and maintaining the:

  • bones
  • joints
  • skin 
  • tendons
  • ligaments
  • blood vessels

Vitamin C supports the immune system to act against viruses, bacteria, and other pathogens. Having low levels of vitamin C can lead to fatigue, joint pain, and insufficient wound healing. 

A diet rich in vitamin C will promote: 

Learn more about when you should take vitamin C here.

What are the best sources of vitamin C?

A variety of multivitamins can provide additional vitamin C in the form of ascorbic acid, sodium ascorbate, calcium ascorbate, and other mineral ascorbates.

Best source

The best way to enjoy the benefits of vitamin C is by eating raw food. This is because prolonged storage or cooking methods can damage the integrity of the nutrient.

The Office of Dietary Supplements suggests that steaming or microwaving foods may retain the most vitamin C.

For more than 200 milligrams (mg) of vitamin C, you can eat 5 servings of fruits and vegetables per day.

Fruits and vegetables  

The following fruits and vegetables have the highest concentrations of vitamin C:

  • oranges
  • strawberries
  • kiwis
  • papayas
  • pink grapefruit juice
  • guava
  • broccoli
  • cauliflower
  • tomatoes 
  • white potatoes
  • bell peppers
  • Brussels sprouts

Learn more about natural food sources of different vitamins here.

The recommended dietary allowance (RDA) for adults ages 19 years and older is 90 mg per day for males and 75 mg for females. 

Children need 15–50 mg per day, depending on their age, while teenagers need 75 mg daily for males and 65 mg daily for females.

People who smoke should add an extra 35 mg of vitamin C per day. 

People who are pregnant or nursing and those recovering from a recent surgery should include additional sources of vitamin C. Your doctor can recommend your specific RDA of vitamin C, depending on your particular health needs.

What are the risks and side effects of vitamin C?

Generally, vitamin C has low toxicity and a low risk of causing adverse effects. Typical side effects of high concentrations of vitamin C include diarrhea, nausea, and abdominal discomfort. High doses of vitamin C may lead to kidney stone formation among people with preexisting kidney disorders.

The tolerable upper level for vitamin C intake among adults is 2,000 mg per day. Getting more than this over a long period of time may increase the risk of adverse side effects.

What happens if you are deficient in vitamin C?

Having a vitamin C deficiency may affect your physical and mental health. A 2020 study suggests that low vitamin C levels may be linked to depression and cognitive impairment.

In addition, a low intake of vitamin C will reduce the body’s ability to make collagen, which can negatively affect different body tissues.

A severe vitamin C deficiency is called scurvy. Scurvy is a relatively rare disease in the United States. It is more prevalent in populations without adequate access to fresh fruits and vegetables. Scurvy can lower a person’s immune function and increase their risk of infection.

Symptoms of deficiency

Some symptoms of vitamin C deficiency include:

Learn more about scurvy here.

Can vitamin C interact with medications?

Always talk with your doctor about adding supplemental sources of vitamin C to your diet, as these can interact with certain medications you may be taking.

Ongoing studies suggest that high concentrations of vitamin C may alter chemotherapy or radiation treatments for people with cancer.

Although doctors may use ascorbic acid to treat certain conditions, it can cause side effects.

Contact your doctor if you develop any of the following symptoms:


Vitamin C is widely known for its antioxidant properties. Among other things, it supports immune system functionality and collagen production.

Since our bodies do not store vitamin C, experts recommend consuming fresh fruits and vegetables every day. Your doctor can recommend the right dosage of supplemental sources according to your health needs.

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Medical Reviewer: Imashi Fernando, MS, RDN
Last Review Date: 2022 Apr 26
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