Collagen synthesis. Vitamin C is an essential coenzyme in collagen synthesis. Cofactor in the hydroxylation of lysine and proline, stimulation of gene-expression in fibroblasts; development, maturation and repair of connective tissue such as skin, bone, tendons ligaments, scar tissue, blood vessels and cartilage (anti-scurvy effect = ascorbic). Lack of ascorbic acid results in poorly formed connective tissue in the skin, joints, muscles, and bones.
Hormone production. Glucocorticoids synthesis in adrenal cortex (stress-response), and Vitamin D-hormone (calcitriol synthesis). Production of epinephrine and norepinephrine, (the hormones released by the adrenal gland in response to stress) are dependent on adequate vitamin C status.
Neurotransmitter metabolism. Ascorbic acid is essential for the production of norepinephrine and serotonin, two important neurotransmitters in the brain. Conversion of tryptophan in 5-hydrotryptophan (=precursor of serotonin), hydroxylation of dopamine into noradrenalin, synthesis of L-dopa.
Amidation of neuro-endocrinic hormones. Gastrin, CRH (corticotropin-releasing- hormone and TRH (tyreotropin-releasing-hormone).
Bile acid synthesis and cholesterol breakdown and excretion. The first key step in the degradation of cholesterol (also tyrosine; bile-acid-synthesis, cholesterol-7-hydroxylasis, HMG-CoA-recductasis) depends on vitamin C. Cholesterol levels in the liver and blood increase if vitamin C status is impaired.
Carnitine synthesis. Ascorbic acid - together with cofactors niacin, vitamin B6, lysine and methione - is essential for the formation of carnitine, an amino acid required for breakdown of fats for energy. Lack of ascorbic acid lowers levels of carnitine and reduces energy production, producing fatigue and muscle weakness.
Tyrosine metabolism. Synthesis and catabolism.
Iron absorbtion and metabolism. Vitamin C sharply increases non-heme iron absorption from diet or supplements. Raising iron transference from transferritin (transport protein) to ferritin (storage protein)-
Folic acid activation. To tetrahydrofolate (THF).
Antioxidant function. Vitamin C is the body’s primary water-soluble antioxidant. It is present in the blood, body fluids, and inside all cells and helps protect against oxidative damage by free radicals of lipids (lipid-peroxidation), proteins, nucleic acid and cell membranes. (anti-inflammatory and anti-degenerative effects, e.g. in cancers, diabetes, arthritis, cataracts and cardiovascular diseases..). Vitamin C is also important in the conversion (reduction) of iron and copper to the form in which they function as cofactors in many enzyme systems, such as reduced copper in superoxide dismutase (another antioxidant).
Antioxidant regeneration. Central building-block in the redox-chain of vitamin C, vitamin E, coenzym Q10 and lipoic acid and/or glutathione, Regeneration of glutathion-disulfide into glutathione.
Vitamin E sparing effect. Regeneration of tocopherol radicals (vitamin E radical) into the reduced, anti-oxidative active alpha-tocopherol (vitamin E).
Protection of folate and vitamin E from oxidation. Ascorbic acid protects folate and vitamin E from oxidation and helps maintain these vitamins in their active forms.
Endothelial cell protection. Raising of NO-bioavailability. (anti thrombotic and blood-lowering effect)
Detoxification and excretion of drugs and chemicals. Ascorbic acid helps maintain the enzyme systems in the liver that detoxify and excrete drugs and toxic environmental chemicals (such as pesticides and heavy metals). Detoxification of xenobiotika (synthesis/anti-oxidative protection of CYP 450) in the liver, excretion of toxins.
Antiviral and antibacterial effect. Vitamin C is important for healthy immune function. It is essential for optimum activity of white blood cells and production of the chemical mediators that direct the immune response. Lack of vitamin C sharply increases vulnerability to infection (Immunocompetence). Stimulation of the cellular (antibodies) and hormonal immune system (interferon), protection of phagocytic membranes from oxidative self-destruction (prolonged function-time of immune cells), activation of complementary systems and of chemotaxis.
Anti.glycation. Inhibition of protein glycosylation and AGE-formation. (e.g. HbA1C).
Anti-allergic. Vitamin C plays a role in controlling body and blood histamine levels (histamine degradation and mast cell stabilization), and blood histamine levels increase when vitamin C status is poor. High levels of histamine can aggravate allergies, asthma, stomach ulcers, and certain psychiatric disorders.
Anti-carcinogenic. Inhibition of the formation of carcinogenic nitrosamines from nitrites and secondary amins (especially of the digestive system), protection of DNA from oxidative damage.