Vitamin C, you may see it referred to as ascorbic acid, is a water soluble antioxidant vitamin found in most fruits and vegetables. Its primary role is in helping the body synthesize collagen, which is a key component of connective tissue, and speed the healing process.
Studies have shown that, as an antioxidant, Vitamin C helps protect against cancer by fighting free radicals and neutralizing preservatives known as nitrites, both of which are linked to increased risk of certain cancers. It is also thought to lower cholesterol levels, helping to protect against heart disease.
Currently, one of the most popular uses of Vitamin C is for reducing the severity of colds and other upper respiratory infections. Research has shown that immune cells have a high concentration of Vitamin C, and that Vitamin C is depleted more quickly during illness.
The most severe form of Vitamin C deficiency is scurvy, a disease characterized by brown spots on the skin, spongy gums, loose teeth, and bleeding. Less severe deficiency can cause weakness, fatigue, achy muscles and joints, bleeding gums, pinpoint hemorrhages, and unexplained bruising.
Recommended daily allowances are set at a minimum required to prevent scurvy and vary by age, with higher recommendations for women who are pregnant or breastfeeding. Tobacco use and nicotine products are known to deplete Vitamin C, so smokers should increase their intake, as should those who are fighting off infection or are prone to infection.
The recommended daily allowance of a vitamin is not the same as upper limits and the recommended upper limit of Vitamin C is 2,000mg, much higher than the recommended daily allowances. Like most water-soluble vitamins, excess Vitamin C is not stored in the body, but excreted in the urine. This means that toxicity, while possible, is fairly uncommon with Vitamin C. Large doses of Vitamin C can cause gastrointestinal distress, cramping, diarrhea, and even, kidney stones in some individuals. The level at which this occurs varies by individual, with some individuals easily tolerating several grams per day of the vitamin, and some sensitive individuals experience effects at doses under a gram per day. If you do find yourself experiencing any of these side effects, lower or discontinue use and you should see relief in a couple of days. Some evidence suggests that excessively high doses of Vitamin C may block absorption of Vitamin B12. Symptoms of a B12 deficiency are very similar to those of Vitamin C toxicity. Taking extra Vitamin B12 with your Vitamin C may also help with these symptoms.
Vitamin C increases the absorption of iron, making it a beneficial vitamin for people with certain types of anemia, and may also aid in the absorption of lutein. Adverse interactions can occur when taking Vitamin C with acetaminophen, antacids with aluminum, aspirin, or blood thinners. Some evidence suggests that excessively high doses of Vitamin C may block absorption of Vitamin B12. Symptoms of a B12 deficiency are very similar to those of Vitamin C toxicity.
Most people are aware that citrus fruits are high in Vitamin C, but citrus isn’t the only good source. Apples, berries, leafy green vegetables, melons, tomatoes, and bell peppers are all great sources of the vitamin. However, Vitamin C is easily destroyed by heat and begins to decline within a few days of harvest, so for maximum benefit, try to eat at least some of your fruits and vegetables raw and as fresh as possible.