Vitamin C vitamins include both L-ascorbic acid (ascorbic acid) and L-dehydroascorbic acid. However, ascorbic acid is the primary dietary form of vitamin C. In most contexts vitamin C, ascorbic acid, and ascorbate are used interchangeably.

Vitamin C is an essential nutrient for humans. However, unlike humans, most other animals and advanced plant species can synthesize vitamin C from other dietary sugars, especially glucose. All animals, including humans, which require vitamin C lack the necessary enzyme L-gulano-gamma-lactone oxidase that is required to synthesize vitamin C from glucose.

The major result of vitamin C deficiency is scurvy. The symptoms of scurvy include bleeding gums, petechiae, ecchymosis, follicular, coiled hairs, hermorrhages, impaired ability to heal from wounds, dry eyes and mouth, joint effusions, muscle weakness, myalgia, fatigue, anemia, anorexia, depression, and kidney disorders. Most of the body’s systems and organs are affected by scurvy.

The major deficiency syndrome of vitamin C is scurvy. Symptoms of scurvy include inflamed and bleeding gums, petechiae, ecchymosis, follicular hyperkeratosis, coiled hairs, perifollicular hemorrhages, impaired wound healing, dry eyes and mouth (Sjögren's syndrome), arthralgia, joint effusions, muscle weakness, myalgia, fatigue, depression, frequent infections, anemia, anorexia, diarrhea, and pulmonary and kidney problems that can lead to coma and death. Basically, scurvy affects all systems of the body.

Vitamin C plays an important role in the formation of connective tissues, including Collagen -- the "glue" that strengthens many parts of the body, including muscles, blood vessels and internal organs. When vitamin C is absent, collagen cannot be properly synthesized, resulting in a collagen like substance with irregular fibrous structure and blood-vessel fragility. This phenomenon explains many of the symptoms of scurvy, especially those relating to connective tissues.

Vitamin C is required to synthesize other important connective-tissues including bone, elastin, fibronectin, and fibrillin. It also helps to regulate the body's ability absorb, transport, and store iron. However, vitamin C is best known for its antioxidant effects and its purported ability to prevent certain degenerative disorders, including heart disease and cancer.

Vitamin C's antioxidant effects are well established. As an antioxidant, one of vitamin C's most important functions is to protect LDL cholestoral (the good cholestoral) from oxidative damage. It is believed that when LDL is damaged only then does cholesterol begin to build up in the body and lead to heart disease. Vitamin C may be one of the best sorces for protection of LDL cholesterol.

A recent study of nearly 1,600 Finnish men, ages 42-60, who were atherosclerosis free, showed that risk of myocardial infarction was considerably higher among those participants with the lowest baseline plasma vitamin c concentrations than among those men with higher levels.

Supplemental vitamin C may be beneficial when used in connection with the following conditions:

• Anemia (if vitamin C deficient exists)
  
• Athletic performance (if vitamin C deficient, or to reduce pain and speed up muscle strength recovery)
  
• Bronchitis
  
• Bruising (for vitamin C deficiency)
  
• Burns (in combination with vitamin E for prevention of sunburn only)
  
• Capillary fragility
  
• Common cold/sore throat
  
• Gingivitis (for periodontal disease and vitamin C deficiency)
  
• Glaucoma
  
• Heart attack (for vitamin C deficiency)
  
• High cholesterol (protection of LDL cholesterol)
  
• Infection
  
• Infertility (for sperm agglutination)