
Vitamin C, or ascorbic acid, is the premier water-soluble antioxidant in the human body.
It prevents oxidative damage to many other molecules in the body and is a powerful reducing agent capable of donating two electrons to other molecules. It prevents electron loss to other molecules that have been oxidized, thereby preserving damaging effects.
Ascorbic acid is involved in protein synthesis. Ascorbic acid is a vital cofactor in the production of collagen, the most abundant protein in the human body. Vitamin C increases enzymes that increase collagen production and protects collagen ribonucleic acid synthesis from damage.
Vitamin C is involved in carnitine production. Carnitine is a molecule that shuttles fat from the cells to mitochondria for production of energy. It is also involved in neurotransmitter production including adrenaline, dopamine and serotonin in the brain and nervous system.
Many animals can make their own vitamin C by converting simple sugars to ascorbic acid. Humans have lost the ability to make their own vitamin C and must get a certain amount in their diets to maintain adequate levels.
The recommended dietary allowance or RDA for adults 19 years or older is 75 milligrams per day to meet minimum requirements and prevent deficiency. For children and young adults, the RDA ranges from 15 to 65 milligrams per day. For nursing mothers and smokers, the RDA is up to 125 milligrams per day.
The highest natural source of vitamin C in any food is the Kakadu plum from Australia. It contains a whopping 2,300 to 3,150 milligrams per 100 grams of fruit. That is 100 times more than the vitamin C content of one orange. One red pepper contains 90 to 110 milligrams of vitamin C. One orange contains 50 to 70 milligrams. One half cup of broccoli contains 40 to 50 milligrams. Generally, fresh fruits and vegetables are good natural sources of vitamin C.
Scurvy is a disease cause by vitamin C deficiency. Symptoms include fatigue, muscle weakness, frequent infections, hair loss, gum disease and bleeding. Although now uncommon in developed countries, it was common in the 17th century throughout the world and was particularly common in people who did not consume fruits and vegetables.
Seafaring sailors who only ate a restrictive diet were particularly susceptible to scurvy. It could prove fatal by serious bleeding and infections if not corrected by dietary measures. The addition of lemon and lime juice or modest consumption of fresh fruit or vegetables helped to dramatically decrease the incidence of scurvy in sailors.
Vitamin C can help prevent gingivitis and periodontal disease. Ascorbic acid is important in maintaining periodontal tissue integrity by improving bone and collagen production. It also helps to maintain the delicate connective tissue integrity lining joints by improving collagen, chondroitin and hyaluronic acid.
Vitamin C supplementation helps to improve outcomes in individuals with blood bacterial infection or sepsis.
Ascorbic acid reduces the amount of time it takes to get better from a cold. It does not necessarily prevent you from getting a cold but can reduce the time it takes to get better by a day or two.
Vitamin C helps the immune system work better by attracting white blood cells called neutrophils to the area of infection, increasing another white blood cell called lymphocytes and macrophages to help engulf foreign invaders.
The use of ascorbic acid in cancer patients remains questionable. Individuals who have the highest blood levels tend to have a lower risk of cancer. Vitamin C supplementation may not help prevent cancer but can be involved in an adjunctive treatment program. It does not lower cholesterol levels but may play a role in preventing oxidative damage to the delicate inner endothelial lining of blood vessels and the heart muscle.
Diets rich in vitamin C provide a reduction in the occurrence of cataracts but supplementation provides mixed results but may also be beneficial in preventing glaucoma and macular degeneration.
Both oral consumption and topical use of vitamin C is beneficial in treatment of sun damage and precancerous skin lesions. The antioxidant effects of ascorbic acid are believed to provide protection from the oxidative damage for sunlight.
It is important to point out dietary consumption of vitamin C-rich foods is generally beneficial to overall health. Foods that contain ascorbic acid are also rich in other compounds such as flavonoids, polyphenols and other beneficial chemicals.
Vitamin C supplementation is generally considered safe at lower doses. A daily supplement of 500 to 1,000 milligrams per day may be beneficial if oxidative stress levels are high. Smokers, or those exposed to smoke from forest fires or other pollutants, may benefit from additional supplementation as well.
Too much vitamin C can cause upset stomach, heartburn, diarrhea and kidney stones in some individuals. Vitamin C is relatively non-toxic for most individuals.
The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.
This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.