Diet & Nutrition - Vitamin C

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin synthesized from glucose. It is the only vitamin for animals that have lost the enzyme Gulonolactone Oxidase, which is the last step in ascorbate synthesis. These animals include primates, bats, guinea pigs and birds. Reactions are:

Function Vitamin C functions primarily as an antioxidant by sacrificing itself to prevent oxidation of other molecules. Vitamin C helps in the formation of collagen, which strengthens the blood vessel wall, forms scar tissue, and provides a matrix for bone growth. Vitamin C also aids in amino acid metabolism and thyroxin synthesis, along with aiding iron absorption. Many believe that vitamin C also helps in the body's ability to fight the flu. Although this has not been fully proven, research has shown that vitamin C improves immune defense.

Ascorbate is involved in two types of general reactions, all of which involve hydroxylation using molecular oxygen:

1. Monooxygenase: depends on Cu ++, O2

ex: Norepinephrine synthesis, peptide hormone amidation

· Synthesis of Norepinephrine in adrenal medulla: Dopamine + O2 + ascorbate, Cu + Norepinephrine + H2O + dehydroascrobate + Cu ++

· Monitoring of peptide hormones: Peptide- (glycine) peptide-NH2 + glyoxylate (CHO-CHOOH)

Includes: CCK, vasopress, gastrin release factor, gastrin, melanotropin, growth hormone release factor, MSH, corticotropin and calcitonin.

2. Dioxygenases: dependent on Fe ++, O2, and a-ketoglutarate ex: carnitine synthesis, tyrosine degradation, collagen hydroxylation

· Hydroxylation of proline and lysine in collagen:

It is found in many extracellular matrix proteins (collagen, elastin), as well as complementary C1q components, and possibly acetylcholineesterase. The ascorbic function here, such as the monooxygenase reaction, acts as a reducing agent for Fe ++ used in the reaction. It is the failure of the hydroxylic collagen that leads to the investigation.

· Tyrosine degradation (4-hydroxyphenyl pyruvate dioxygenase):

Decreased levels of ascorbate cause a decrease in muscle carbohydrate levels, thereby reducing the oxidation of fatty acids in the mitochondria. Muscles are synthesized on proteins and thus released upon protein degradation; it is found in proteins such as histones, calmodulin, myosin, cytochrome c. In general, if you lose vitamin C, you will experience a decrease in carnitine and thus a reduction in beta-oxidation and thus muscle must rely on other forms of energy as it cannot efficiently transfer fatty acids into the mitochondria.

Scurvy deficiency is a name given to someone who does not have vitamin C. The recognition of scurvy symptoms began in the Papryrus of Elber, Egypt, about 1550 BC. Documentation of scurvy symptoms also existed during the exploration of Jacques Cartier in 1535. At this time Native Americans taught Cartier to use white cedar extracts in treating his browser who died of scurvy. At the time, no one knew exactly what caused this, until a British doctor decided to conduct a study that provided some salmon with lemon juice. Those who use lime juice do not experience scurvy, thus giving them the name "limeys". Eventually the factor was isolated from the juice of the lemon and was found to be a 6-carbon glucose structure called ascorbic acid (vitamin C).

Symptoms include microcytic anemia, bleeding, bleeding gums, muscle deterioration, joint pain, and failure to heal. Vitamin C, however, can be easily reversed by taking a moderate dose of suction.

Symptoms of scurvy: o Soft bones (loss of collagen matrix, possible loss of sulfonation) o Rubber bleeding, loose teeth (loss of cell matrix) o Capillary bleeding (loss of extracellular matrix supporting capillaries) o Slow wound healing (depending on collagen and extracellular matrix o o Curly hair (changes in collagen structure in hair) o Psychosis, hysteria, depression (Loss of neurotransmitters ??)

Individuals are at risk for developing vitamin C deficiency with increased steroid or aromatic drug use. This increases the need for ascorbate for hydroxylate and removes compounds from the body. Examples of these types of drugs include: oral contraceptives, toxins, barbiturates and stress-related glucocorticoids.

Individuals who smoke cigarettes also have a high need for vitamin C. These individuals have significantly lower serum concentrations. It is believed to be caused by toxins in the smoke that promote harmful oxidation and free radical reactions in the lungs and body; prevention and correction of this reaction overcomes the body of ascorbate. Smokers are recommended to increase their intake of ascorbate to 100 mg / day.

Toxicity Although vitamin C is a water-soluble vitamin, supplementing with excess vitamin C can be dangerous. In some individuals, high doses can cause iron toxicity as a result of their stimulatory effects.

Sources of citrus fruits (i.e. citrus, kiwi, and mango) or cabbage-type vegetables (i.e. spinach) o dark green vegetables (i.e. broccoli, peas, and vegetable) o papaya o cantaloupe o strawberries o red pepper tomato or potato

Diet & Nutrition - Vitamin C


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