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Vitamin C - Ascorbic Acid

Ascorbic acid is often consumed as some named form of ascorbate, for example, calcium ascorbate.

Vitamin C is one of the most important vitamins for the immune system and for the health of every tissue in the body. Vitamin C is water-soluble so our bodies are unable to store it. Therefore we must ensure that we consume adequate supplies every day.

The functions of vitamin C

Vitamin C is necessary for normal growth and development. It is required for:

Antioxidants are nutrients that block some of the damage caused by free radicals, which are by-products that result when your body transforms food into energy. The build up of these by-products over time is largely responsible for the aging process and can contribute to the development of various health conditions such as cancer, heart disease, and a host of inflammatory conditions like arthritis. Antioxidants also help reduce the damage to the body caused by toxic chemicals and pollutants such as cigarette smoke.

The symptoms and signs of vitamin C deficiency

Vitamin C deficiency can lead to:

A severe form of vitamin C deficiency is known as scurvy, which mainly affects older, malnourished adults.

The body does not manufacture vitamin C on its own, nor does it store it. So it is very important to include plenty of vitamin C-containing foods in your daily diet.

Food sources of vitamin C

All fruits and vegetables contain some amount of vitamin C. Foods that tend to be the highest sources of vitamin C include: green peppers, citrus fruits and juices, strawberries, tomatoes, broccoli, turnip greens and other leafy greens, sweet and white potatoes, and cantaloupe.

Other excellent sources include: papaya, mango, watermelon, brussels sprouts, cauliflower, cabbage, winter squash, red peppers, raspberries, blueberries, cranberries, and pineapples.

How much do you need?

The recommended daily intakes of dietary vitamin C (according to the U.S. RDA) are listed below.

Pediatric (for children)

Vitamin C Pediatric RDA
Stage and Age Vitamin C (mg)
Neonates 1 to 6 months 30 mg
Infants 6 to 12 months 35 mg
Children 1 to 3 years 40 mg
Children 4 to 6 years 45 mg
Children 7 to 10 years 45 mg
Children 11 to 14 years 50 mg
Adolescent girls 15 to 18 years 65 mg
Adolescent boys 15 to 18 years 75 mg


Vitamin C Adults RDA
Males and Females Vitamin C (mg)
Men over 18 years 90 mg
Women over 18 years 75 mg
Breastfeeding women: first 6 months 95 mg
Breastfeeding women: second 6 months 90 mg

Special notes

Being water soluble, vitamin C is regularly excreted by the body. Therefore, toxicity is very rare, although large doses can cause skin irritation, stomach upset and diarrhea. Vitamin C will be more effective if taken with bioflavonoids, calcium and magnesium. To enhance the antioxidant properties, it will be best to take it with the other antioxidants, as there is strong evidence of synergy between all of them.

Mega doses of vitamin C should be avoided in individuals with a history of renal stones due to oxalate formation or hemochromatosis or other diseases related to excessive iron accumulation.

Extremely high dosage of vitamin C may predispose premature infants to hemolytic anemia due to the fragility of their red blood cells.

The need for vitamin C will dramatically increase in times when the body is subjected to trauma, infections, and strenuous exercise, elevated environmental temperatures or if the person is a smoker. Smokers should supplement with another 100 mg per day.

Carbon monoxide destroys vitamin C so anyone living in polluted areas will need extra vitamin C.

Be careful of taking aspirin and vitamin C supplements together. Vitamin C may cause stomach irritation.

Vitamin C is destroyed by air, heat, water as well as prolonged storage, overcooking and processing. Antacids, alcohol, antidepressants, birth control pills and steroids will also deplete this vitamin.

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Bland, J. 1996, Contemporary Nutrition. J & B Associates.

Davies, S. and A. Stewart., 1997, Nutritional Medicine. Pan.

Holden, S., Hudson, K., Tilman, J. & D. Wolf, 2003, The Ultimate Guide to Health from Nature. Asrolog Publication.

Pressman, A. and S. Buff, 2000, The Complete Idiot's Guide to Vitamins and Minerals. (2nd Ed.) Alpha Books.

Soothill, R. 1996, The Choice Guide to Vitamins and Minerals. A Choice Book Publication.

Sullivan, K. 2002, Vitamins and Minerals: A Practical Approach to a Health Diet and Safe Supplementation. Harper Collins.

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Vitamin C can alter the results of blood and urine testing, including those for diabetes. (If you have any tests performed, let your physician know if you are taking vitamin C supplements.)