The health benefits of vitamin C are abundant and varied, but it's probably best known as a cell protector, immunity booster, and powerful Antioxidant. The body's ligaments, tendons, and Collagen (a Protein found in connective tissues) rely on the presence of vitamin C to stay strong and healthy. Like all antioxidants, vitamin C counters the effects of cell-damaging molecules called Free radicals. As an added benefit, it even helps the body recycle other antioxidants. For certain conditions, vitamin C is best taken with other antioxidants, such as vitamin E, flavonoids, and carotenoids.

Specifically, vitamin C may help to:

Lessen the severity and duration of colds and flu. Taking vitamin C at the first sign of a cold or the flu may keep the illness from fully developing, and you'll probably recover faster. (1) In a 1995 review of studies investigating the effect of vitamin C on colds, researchers concluded that doses of 1,000 to 6,000 mg a day at the onset of symptoms reduced a cold's duration by 21%, and shortened its duration by one day on average. Taking vitamin C doesn't prevent colds, however. (2)

Speed wound healing and minimize the effects of bruising. Vitamin C helps the body to repair and maintain itself by reinforcing cell walls and helping to strengthen tiny blood vessels called Capillaries. It further accelerates healing by inhibiting Inflammation.

Keep gums strong and healthy. When taken daily, vitamin C protects gum tissue against cell damage and speeds healing in this delicate area. It's often taken with flavonoids for this purpose. Brushing the gums with vitamin C powder can also minimize inflammation and bleeding. (3)

Increase resistance to heart disease (and Angina) by improving cholesterol levels. Several studies have linked the presence of low levels of vitamin C to a greater risk of angina and heart attacks in people with existing heart disease. (4-8) Research also indicates that, when taken with vitamin E, vitamin C helps protect LDL ("bad") cholesterol from oxidation, thus preventing plaque buildup in coronary arteries. (9) Vitamin C may also boost blood levels of HDL ("good") cholesterol; studies are ongoing to provide definitive evidence of this action.

Prevent certain cancers. As a powerful antioxidant, vitamin C may help to fight cancer by protecting healthy cells from free-radical damage and inhibiting the proliferation of cancerous cells. (10, 11) Specifically, recent studies have shown that the vitamin may help stave off cancers of the stomach and esophagus by blocking the conversion of nitrates and nitrites into cancer-causing compounds. (12, 13) Debate over the value of vitamin C for cancer treatment and prevention is fierce, however, with some studies finding no benefit—or even drawbacks—from vitamin C supplementation, while others report prolonged survival in cancer patients, especially when it's taken along with vitamin E.

Protect against cataracts. Vitamin C may keep the lens of the eye from being damaged by cigarette smoke and ultraviolet (UV) light, both types of exposure linked to cataract formation. One study showed that women who took vitamin C supplements for 10 years or more had a 77% lower risk of "lens opacities," the beginning stage of cataracts, than women who didn't use supplements. (14)

Relieve allergies, eczema, sinusitis, and asthma. Vitamin C is a natural Antihistamine capable of blocking the effect of inflammatory substances some people produce in response to allergens such as pollen and pet dander. (15, 16) Allergies are often an underlying cause of sinusitis and may also trigger the intensely itchy rashes associated with eczema. Vitamin C is frequently recommended with other antioxidants such as flavonoids for sinusitis. Numerous studies have shown that vitamin C helps prevent or improve asthmatic symptoms as well; asthma sufferers are often deficient in this and other vitamins. Vitamin C has also been shown to help exercise-induced asthma attacks, in some cases thwarting an attack if taken in an adequate dose right before a workout. (17) Adults with exercise-induced asthma may want to experiment with doses from 500 mg to 5000 mg.

Prevent migraines. Taken along with pantothenic acid, vitamin C boosts the production of hormones that help the body deal with the adverse effects of stress-induced migraines.

Improve memory. As an antioxidant, vitamin C plays a key role in maintaining healthy nerve cells, and is often taken in combination with vitamin E, mixed carotenoids, ginkgo biloba, and coenzyme Q₁₀ to help prevent memory loss. Several observational studies and one clinical controlled study have found that vitamin C may be beneficial in preventing the development of Alzheimer dementia. (18)

Fight chronic fatigue syndrome. Vitamin C taken with mixed carotenoids helps strengthen a weakened immune system, believed by many to be a factor in this disabling disorder. (19)

Control gallstone formation. Sometimes gallstones develop when bile contains high concentrations of cholesterol. Vitamin C may help to lower the risk of this occurring by reducing bile cholesterol levels. (20)

Combat the effects of aging and extend life. Used in combination with other antioxidants, such as vitamin E and flavonoids, vitamin C may combat the deteriorative effects of aging (such as wrinkles) caused by free-radical damage. (21) It may also help you live longer. In one study, men who took more than 300 mg of vitamin C a day (from food and supplements) lived longer than men who consumed less than 50 mg a day.

• Large doses of vitamin C may cause a false positive result for glucose in the urine.
• If you have hemochromatosis, a genetic tendency to store excess iron (vitamin C enhances iron absorption), don't take more than 500 mg of vitamin C a day.
• Vitamin C can distort the accuracy of medical tests for colon cancer and Hemoglobin levels. Let your doctor know if you're taking vitamin C supplements.