Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement. Humans, unlike most animals, are unable to synthesize vitamin C endogenously, so it is an essential dietary component.
Vitamin C is required for the biosynthesis of collagen, L-carnitine, and certain neurotransmitters; vitamin C is also involved in protein metabolism.
Vitamin C is found in a wide variety of fruit and vegetables. Good sources include:
- oranges and orange juice
- red and green peppers
- brussels sprouts
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 are good sources.
Applications of Vitamin C
Historically, vitamin C was used for preventing and treating 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 conditions, bronchitis, human immunodeficiency virus (HIV) disease, stomach ulcers 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 or inflammation of the bladder and prostate, nerve pain, and complications during pregnancy.
Some people use vitamin C for depression, thinking problems, dementia, Alzheimer’s disease, physical and mental stress, fatigue including chronic fatigue syndrome (CFS), autism, attention deficit-hyperactivity disorder (ADHD), schizophrenia, Lou Gehrig’s disease, and Parkinson’s disease. It is also used to treat or prevent toxicity caused by certain drugs or metals and to treat peptic ulcers, swine flu, sudden hearing loss, gout, and tetanus.
Other uses include increasing the absorption of iron from foods. Vitamin C is also used in combination with a drug called deferoxamine to increase removal of iron from the blood. Some people use vitamin C to correct a protein imbalance in certain newborns (tyrosinemia). It is also used to prevent the transfer of HIV from mothers to babies during breastfeeding. Vitamin C is also used to help reduce the side effects of bowel preparation.