Vitamin C is required for the biosynthesis of collagen, L-Carnitine and certain neurotransmitters; it is also involved in protein metabolism. Collagen is an essential component of connective tissue which helps aid the body’s healing process. Vitamin C is also a physiological antioxidant that has the ability to create other antioxidants in the body, this makes it an important part of immune function. It also improves the absorption of iron that is found in plants. Extended periods of Vitamin C restriction can lead to scurvy.
Fruits and vegetables are the best sources of Vitamin C. Citrus fruits, bell peppers, kiwis, broccoli, strawberries, brussels sprouts, cabbage, tomatoes, cauliflower, spinach and potatoes are all excellent sources of Vitamin C. Ascorbic acid(a synonym for Vitamin C) is water soluble and can be destroyed by heat which means certain methods of food preparation can significantly alter Vitamin C content. If eating food specifically for Vitamin C content the food should be consumed raw as often as possible and at peak freshness. If you do cook vegetables, steaming them minimizes vitamin loss when compared to other methods of preparation.
Vitamin C supplements are usually available in the form of ascorbic acid. Ascorbic acid has been show to have the same bioavailability(proportion of a substance that enters the circulation when introduced to the body and so is able to have an active effect) as that found in fruits and vegetables. Ascorbic acid base Vitamin C supplements have been proven to be effective and they are also relatively inexpensive making them among the most popular supplements overall.
Acute Vitamin C deficiency leads to scurvy. Symptoms of scurvy take around a month to begin appearing once Vitamin C intakes falls beneath 10mg/day. The first signs of scurvy are fatigue and swelling of the gums; once it progresses it leads to a litany of terrible effects which include joint pain due to the loss of connective tissue, loss of teeth and bleeding of the gums. If left untreated scurvy will ultimately lead to death. Scurvy was common among sailors who undertook long voyages until the 18th century when it was discovered that citrus fruit could fend it off. Scurvy is now extremely rare in developed countries.
Even though scurvy is now rare amongst developed populations, chronic Vitamin C deficiency is still relatively common. The populations who are most at risk of Vitamin C deficiency are smokers, infants who are fed boiled or evaporated milk, people with limited food variety and people who suffer from intestinal malabsorption problems.
Vitamin C may be helpful in both cancer protection as well as cancer treatment due to its ability to limit the formation of carcinogens. Case studies have shown an inverse relationship between dietary Vitamin C and many different prevalent forms of cancer. It also leads to a reduced risk of cardiovascular disease as the anti-oxidants found in Vitamin C lead to less oxidative damage as well as improved nitric oxide production and vasodilation which improves blood flow and reduces the buildup of plaque. Vitamin C also reduces the risk of Age Related Macular Degeneration and glaucoma, and may even shorten the duration of the common cold. There are minimal risks associated with excess Vitamin C intake due to its water solubility.