Although vitamins are “vital” nutrients required for life that, in most cases, cannot be synthesized by the body, vitamin C stands out because, in addition to humans, there are few animals that actually lack this ability. Vitamin C is a water-soluble vitamin and antioxidant commonly called ascorbic acid. Our bodies neither make nor store vitamin C, so we must obtain it from an external source and replenish it on a regular basis. We can get sufficient levels of vitamin C from our diets—almost all fruits and vegetables contain it. Furthermore, vitamin C is the most widely consumed nutritional supplement. It is available in several forms, such as tablets, capsules, crystals, and drink mixes.
When consumed via diet or supplement, vitamin C is absorbed in the intestinal tract and transported via glucose mechanisms. Keep in mind, large quantities of sugar in the intestines or blood can slow vitamin C absorption. Also, cooking can diminish vitamin C content in vegetables by 60 percent through enzymatic destruction, particularly with longer cooking times or by using copper cookware.
Vitamin C is essential for many physiologic processes, and it is a cofactor in eight known enzymatic reactions, including several for collagen synthesis. In addition, vitamin C plays an important role in building and repairing tissue in all body parts including skin, tendons, ligaments, and blood vessels. It also helps heal scars and maintain cartilage, bones, and teeth. According to the National Institutes of Health, the recommended daily dietary allowance for vitamin C is 90 mg in men and 75 mg in women. However, many studies have indicated these recommendations are far too low.
Recent research has shown high doses of vitamin C are effective in fighting cancer. The beneficial mechanism occurs when iron and other metals react with vitamin C to create hydrogen peroxide. The energy centers of tumor cells (mitochondria) are susceptible to high concentrations of hydrogen peroxide, which deprives them of energy and initiates cell death. Hydrogen peroxide also damages the DNA of cancer cells, disrupting cell replication. The body, however, limits absorption of oral vitamin C in the intestines, so the only way to boost vitamin C concentration to levels high enough to kill cancer cells is intravenous administration.
The most commonly perceived benefit of vitamin C may be that it can cure the common cold, but a review of existing research fails to provide a verdict. Although vitamin C taken in large doses may reduce the length of a cold, evidence does not appear to support its use as a preventative measure. Immune cells tend to hoard vitamin C and have been found to deplete their supply rapidly when faced with an infection. Although the jury is still out on its direct association with the common cold, vitamin C does play a vital role in the immune system.
Therefore, it is important to maintain healthy vitamin C levels, and you can detect vitamin C deficiency in several ways. Some of the most common signs include fatigue, mood changes, weight loss, joint and muscle aches, bruising, dental conditions, dry hair and skin, and infections. In extreme cases when vitamin C deficiency lasts 3 or more months, scurvy can develop. As with anything, too much can be bad. Vitamin C overdose symptoms include indigestion and diarrhea. However, when determining how much vitamin C is necessary, keep in mind that overdosing is rare.
Vitamin C Is in Season
Try the following fruits and veggies for rich flavor and tons of vitamin C to boot.
- Citrus fruit eg. oranges, lemon, lime, and grapefruit
- Berries especially strawberries, raspberries, blueberries, and cranberries
- Cauliflower, broccoli, and Brussels sprouts
- Green and red peppers
- Potatoes, both white and sweet
- Spinach, cabbage, and other
By John Benson