Everything You Need to Know About Vitamin C

Vitamin C is an essential micronutrient without which, our bodies would not be able to function properly. Unlike some other vitamins, our bodies are not able to store vitamin C—so regular intake of vitamin C-rich foods is crucial.

What exactly is vitamin C, and why is it so important? Read on to find out!

What is vitamin C?

Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin that is essential in many functions of the body. Vitamin C is unable to be synthesized by humans, which means that we need to get it from food sources.

Vitamin C is found in fruits and vegetables, and is also available in supplements in the form of capsules or chewable tablets.

What is the function of vitamin C in the body?

Vitamin C is needed for normal growth and development. It is involved in biosynthesis of collagen, L-carnitine, and certain neurotransmitters. It is also involved in protein synthesis.

Vitamin C helps to form protein that makes up skin, tendons, ligaments, and blood vessels. It heals wounds and forms scar tissue; repairs and maintains cartilage, bones, and teeth; and aids in the absorption of iron.

Vitamin C is also an antioxidant. This means that is helps to fight free radicals— dangerous toxins in the body which can alter normal cell DNA and lead to early aging, inflammatory disease, and cancer. Vitamin C fights free radicals by repairing damaged cells, minimizing free radical attack, and reducing the amount of free radicals in the body.

Vitamin C Health Benefits:

A lot of research has been done to prove the health benefits of vitamin C including its potential in reducing the severity and duration of the common cold, its contribution to cardiovascular health, and its ability to fight cancer.

Research shows us that vitamin C can provide the following health benefits, when consumed daily:

  • Wards off Common Cold
  • Boosts immune function
  • Treats high blood pressure
  • Cures lead toxicity
  • Prevents cataracts
  • Prevents cancer
  • Combats stroke
  • Controls asthma
  • Reduces healing time for wounds
  • Prevents early aging
  • Reduces chronic inflammation and prevents inflammatory disease
  • Reduces the risk of cardiovascular disease

How much vitamin C do I need?

According to the National Institutes of Health (NIH), the recommended daily intake of vitamin C is as follows:

  • Age 0-6 months: 40 mg
  • Age 7-12 months: 50 mg
  • Age 1-3 years: 15 mg
  • Age 4-8 years: 25 mg
  • Age 9-13 years: 45 mg
  • Males, age 14-18 years: 75 mg
  • Females, age 14-18 years: 65 mg
  • Males, age 19+: 90 mg
  • Females, age 19+: 75 mg
  • Pregnancy: 85 mg
  • Lactation: 120 mg

Is there such a thing as too much vitamin C?

For most people, large amounts of vitamin C as part of a balanced diet will do no harm. Since vitamin C is not stored in the body, the extra is flushed out in your urine.

The recommended daily amount of vitamin C is 65 to 90 milligrams (mg) for an adult, although the upper limit is 2,000 mg, which is about 22 times the recommended daily amount. That means that you can consume a lot of vitamin C, and it’ll still be safe.

Any more than that, and you may gastrointestinal experience symptoms including diarrhea, nausea, vomiting, heartburn, and bloating, as well as headache, according to the Mayo Clinic. Long-term megadoses may cause insomnia and kidney stones— although it is unlikely that you will consume amounts large enough on a regular basis, to experience these symptoms.

According to the NIH, the Food and Nutrition Board (FNB) established safe and tolerable upper intake levels of vitamin C— long-term intake above the recommended upper levels may lead to adverse health effects. The recommendation begins from age 1.

This is the recommendation for the most vitamin C a person can consume daily.

  • Age 1-3 years: 400 mg
  • Age 4-8 years: 650 mg
  • Age 9-13 years: 1,200 mg
  • Age 14-18 years: 1,800 mg
  • Pregnancy and lactation: 2,000 mg

Which foods are good sources of vitamin C?

Vitamin C can be found in abundance in many fruits and vegetables. The best sources of vitamin C are:

  • Guava,1 cup—377 mg; 628% DV
  • Bell Peppers, 1 cup—190 mg; 317% daily value (DV)
  • Kiwifruit, 1 cup—167 mg; 278% DV
  • Strawberries, 1 cup—98 mg; 163% DV
  • Oranges, 1 cup—95.8 mg; 160% DV
  • Papaya, 1 cup—88.3 mg; 147% DV
  • Broccoli, 1 cup—81.2 mg; 135% DV
  • Kale, cooked, 1 cup—53.3 mg; 89% DV
  • Brussels sprouts, ½ cup—48.4 mg; 81% DV

Many other fruits and vegetables are excellent sources of vitamin C, including citrus fruits, tomatoes, cruciferous vegetables (e.g. broccoli, cauliflower, cabbage, kale), and peas.

Since vitamin C is not stored in the body, we need to eat foods high in vitamin C daily to ensure a steady supply.

Vitamin C is also available as supplements, in many different forms. Some people take vitamin C at first sign of a cold, because it supports immune function and is used more quickly by the body when fighting off foreign invaders.

What are the symptoms and long-term risks of vitamin C deficiency?

Vitamin C deficiency causes a disease called scurvy. Scurvy is commonly known as the disease which affected sea-travelers until the early 20th century—when the cause was discovered. Sea-travelers would be out at sea for long periods of time with no fresh produce, consuming little to no vitamin C for as long as their travel required.

Symptoms of scurvy appear after only one month of vitamin C deficiency—with as little as 10 mg or less of vitamin C per day. Left untreated, scurvy can be fatal.

Early signs of scurvy include general symptoms such as:

  • Weakness
  • Fatigue
  • Malaise
  • Inflammation of the gums
  • Bleeding gums
  • Poor wound healing
  • Dry and brittle hair
  • Red or purple discolored spots on the skin
  • Dry, rough, and scaly skin
  • Bruising
  • Nosebleeds
  • Digestive disorders
  • Swollen and painful joints
  • Left untreated, long-term vitamin C deficiency can cause:
  • Depression
  • Anemia
  • High blood pressure
  • Gallbladder disease
  • Stroke
  • Cancer
  • Atherosclerosis
  • Death

Scurvy is rare in developed countries, but can still occur in people with limited diets.

Who is at risk for vitamin C deficiency?

People who live in developing countries, and those who suffer malnutrition are at risk for vitamin C deficiency. Refugees, who may not have access to fresh foods for long periods of time have 5-45% rate of vitamin C deficiency.

Smokers. Due to increased oxidative stress in the body, smokers have on average, lower plasma and leukocyte vitamin C levels. Smokers are recommended to have 35 mg more vitamin C per day than the average nonsmoking adult.

People with malabsorption. Certain medical conditions or medications may reduce the absorption of vitamin C or increase the amount needed.

Infants fed evaporated or boiled milk. Infants require either breastmilk or baby formula, both of which contain adequate amounts of vitamin C. Infants who are fed boiled or evaporated animal milk may suffer from vitamin C deficiency.

People with limited food variety. Most people are able to get enough vitamin C through a varied diet. According to the NIH, “people who have limited food variety—including some elderly, indigent individuals who prepare their own food; people who abuse alcohol or drugs; food faddists; people with mental illness; and, occasionally, children—might not obtain sufficient vitamin C.”

How is vitamin C deficiency treated?

Vitamin C deficiency can be treated with oral vitamin C supplements, as well as with foods high in vitamin C.

If you think you may be lacking in certain nutrients, ask your doctor about taking a multivitamin, and which one would be best for you.

Should I take a vitamin C supplement?

If you are eating a balanced diet high in fresh fruits and vegetables, you probably do not need to take a vitamin C supplement.

Research does show, however, that regular doses of over 100% DV of vitamin C can help ward of the common cold, disease, and even cancer— just be sure not to consume more than the recommended upper intake levels, mentioned above.

Prenatal vitamins and multivitamins will most likely contain all the vitamin C you need, so extra supplementation is usually unnecessary. If you are pregnant, consult with your doctor before taking any extra supplements or medications.


  1. Delanghe JR, Langlois MR, De Buyzere ML, Torck MA. Vitamin C deficiency and scurvy are not only a dietary problem but are codetermined by the haptoglobin polymorphism. Clin Chem. 2007 Aug. 53(8):1397-400.
  2. Al-Dabagh A, Milliron BJ, Strowd L, Feldman SR. A disease of the present: scurvy in “well-nourished” patients. J Am Acad Dermatol. 2013 Nov. 69 (5):e246-7.
  3. Centers for Disease Control and Prevention. NHANES 2005-2006. Available at https://www.cdc.gov/nchs/nhanes/nhanes2005-2006/lab05_06.htm. Accessed: September 14, 2012.
  4. World Health Organization/NHD 99.11 Scurvy and its prevention and control in major emergencies. World Health Organization. Available at https://www.who.int/nutrition/publications/emergencies/WHO_NHD_99.11/en/. Accessed: July 28, 2011.
  5. [Guideline] Dietary Reference Intakes from the Food and Nutrition Board, Institute of Medicine, National Academies. National Academies of Sciences, Engineering, Medicine. Available at https://nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/1_%20EARs.pdf?la=en. 2012;

Leave a Comment