Q. What is vitamin C and what are its benefits?
A.Vitamin C is a vitamin. Some animals can make their own vitamin C, but people must get this vitamin from food and other sources. Good sources of vitamin C are freshfruits and vegetables, especially citrus fruits. Vitamin C can also be made in a laboratory. Most experts recommend getting vitamin C from a diet high in fruits and vegetables rather than taking supplements. Fresh-squeezed orange juice or fresh-frozen concentrate is a better pick than ready-to-drink orange juice. The fresh juice contains more active vitamin C. Drink fresh-frozen orange juice within one week after reconstituting it for the most benefit. It you prefer ready-to-drink orange juice, buy it 3 to 4 weeks before the expiration date, and drink it within one week of opening. Historically, vitamin C was used for preventing and treating scurvy. Scurvy is now relatively rare, but it was once common among sailors, pirates, and others who spent long periods of time onboard ships. When the voyages lasted longer than the supply of fruits and vegetables, the sailors began to suffer from vitamin C deficiency, which led to scurvy. These days, vitamin C is used most often for preventing and treating the common cold. Some people use it for other infections including gum disease, acne and other skin infections, bronchitis, human immunodeficiency virus (HIV) disease, stomachulcers caused by bacteria called Helicobacter pylori, tuberculosis, dysentery (an infection of the lower intestine), and skin infections that produce boils (furunculosis). It is also used for infections of the bladder and prostate. Some people use vitamin C for depression, thinking problems, dementia,Alzheimer's disease, physical and mental stress, fatigue, and attention deficit-hyperactivity disorder (ADHD). Other uses include increasing the absorption of iron from foods and correcting a protein imbalance in certain newborns (tyrosinemia). There is some thought that vitamin C might help the heart and blood vessels. It is used for hardening of the arteries, preventing clots in veins and arteries, heart attack, stroke, high blood pressure, and high cholesterol. Vitamin C is also used for glaucoma, preventing cataracts, preventing gallbladderdisease, dental cavities (caries), constipation, Lyme disease, boosting the immune system, heat stroke, hay fever, asthma, bronchitis, cystic fibrosis, infertility, diabetes,chronic fatigue syndrome (CFS), autism, collagen disorders, arthritis and bursitis,back pain and disc swelling, cancer, and osteoporosis. Additional uses include improving physical endurance and slowing aging, as well as counteracting the side effects of cortisone and related drugs, and aiding drug withdrawal in addiction. Sometimes, people put vitamin C on their skin to protect it against the sun, pollutants, and other environmental hazards. Vitamin C is also applied to the skin to help with damage from radiation therapy.

Q.How does Vitamin C work?
A.Vitamin C is required for the proper development and function of many parts of the body. It also plays an important role in maintaining proper immune function.

Q.What are the uses of Vitamin C?
A. Treatment and prevention of vitamin C deficiency, including a condition called “scurvy.”
Improving the way the body absorbs iron.
Treating a disease called tyrosinemia in newborns when given as an injection.
Wrinkled skin. Skin creams containing vitamin C or vitamin C in combination with acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum) seem to improve wrinkles in facial skin aged by sun exposure.
Reducing the risk of certain cancers of the mouth and breast. This only works when fresh fruits and vegetables high in vitamin C are eaten, not with vitamin C supplements.
Treating the common cold. There is a lot of controversy about the effectiveness of vitamin C for treating the common cold. However, the majority of evidence shows that taking high doses of vitamin C might shorten the course of the cold by 1 to 1.5 days in some patients. But it is not effective for preventing the common cold.
Lowering high blood pressure. Taking vitamin C along with conventional high blood pressure medications appears to decrease systolic blood pressure (the top number in a blood pressure reading) by a small amount, but does not seem to decrease diastolic pressure (the bottom number). Taking vitamin C supplements alone, though, doesn’t seem to affect blood pressure.
Preventing sunburn. Taking vitamin C along with vitamin E seems to prevent sunburn. But taking vitamin C alone doesn’t prevent sunburn.
Reducing the risk of gallbladder disease. There is some evidence that taking vitamin C might help to prevent gallbladder disease in women. But vitamin C doesn’t seem to have this effect in men.
Slowing the worsening of osteoarthritis. Obtaining vitamin C from dietary sources seems to prevent cartilage loss and worsening of symptoms in people with osteoarthritis.
Treating an eye disease called AMD (age-related macular degeneration) when used with other medicines. Taking vitamin C in combination with zinc, vitamin E, and beta-carotene daily seems to help prevent vision loss or slow worsening of AMD in patients with advanced AMD. There isn't enough evidence to know if this combination helps people with less advanced macular disease or prevents AMD. Using vitamin C with other antioxidants, but without zinc, doesn't seem to have any effect on AMD.
Decreasing protein in the urine of people with type 2 diabetes (albuminuria). This might help to lower the risk of developing serious kidney disease.
Redness (erythema) after cosmetic skin procedures. There is some evidence that a particular vitamin C skin cream can decrease the amount of redness and the time it lasts following laser resurfacing for scar and wrinkle removal.
Decreasing lung infections caused by heavy exercise. Using vitamin C in amounts of 600 mg to 1 gram per day before heavy physical exercise, such as a marathon, might prevent upper respiratory infections that sometimes follow heavy exercise.
Treating ulcers in the stomach caused by bacteria called H. pylori. Taking vitamin C seems to decrease some of the side effects caused by treatment. After H. pylori bacteria are killed, vitamin C appears to decrease the occurrence of precancerous changes in stomach tissue.
Helping medicines used for chest pain, such as nitroglycerin, to work longer.
Reducing the risk in women of a circulatory system disorder called peripheral arterial disease.
Preventing “hardening of the arteries” (atherosclerosis).
Preventing kidney problems related to contrast media used during a diagnostic test called angiography.
Reducing human immunodeficiency virus (HIV) transmission by mothers to their newborns when taken with vitamins B and E.
Reducing complications after a broken wrist called complex regional pain syndrome, or reflex sympathetic dystrophy.
Reducing lead in the blood by eating foods high in vitamin C.
Reducing complications of a high-risk pregnancy (pre-eclampsia).
Improving physical performance and strength in the elderly.