Diet & Nutrition – Vitamin C

Vitamin C, often known as ascorbic acid, is a water-soluble vitamin synthesized from glucose. It is just a vitamin for animals which have misplaced the enzyme Gulonolactone Oxidase, which is the final step in ascorbate synthesis. These animals embrace primates, bats, guinea pigs and perching birds. The response is:

Capabilities Vitamin C capabilities primarily as an antioxidant by sacrificing itself as a way to stop the oxidation of different molecules. Vitamin C helps to type collagen, which strengthens blood vessel partitions, types scar tissue, and gives a matrix for bone progress. Vitamin C additionally aids within the metabolism of amino acids and thyroxin synthesis, together with aiding within the absorption of iron. Many consider that vitamin C additionally aids within the physique’s potential to battle off a chilly. Though this has not been utterly confirmed, analysis has proven that vitamin C does enhance the physique’s immune defenses.

Ascorbate is concerned in 2 basic sorts of reactions, all of which contain hydroxylation utilizing molecular oxygen:

1. Monooxygenase: are dependent upon Cu++, O2

ex: Norepinephrine synthesis, peptide hormone amidation

· Norepinephrine synthesis within the adrenal medulla: Dopamine + O2 + ascorbate, + Cu+ Norepinephrine + H2O + dehydroascrobate + Cu++

· Peptide hormone amidation: Peptide-(glycine) peptide-NH2 + glyoxylate (CHO-CHOOH)

Consists of: CCK, vasopression, gastrin releasing issue, gastrin, melanotropin, progress hormone launch issue, MSH, corticotropin and calcitonin.

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

· Hydroxylation of proline and lysine in collagen:

That is discovered on many proteins of the extracellular matrix (collagen, elastin), in addition to on C1q element of the complement, and perhaps on acetylcholinesterase. The operate of the ascorbate right here, like that of the monooxygenase reactions, is to function a lowering agent for the Fe++ used within the response. It’s the failure of hydroxylate collagens that results in survey.

· Tyrosine Degradation (4-hydroxyphenyl pyruvate dioxygenase):

Decreased ascorbate ranges ends in decreased muscle carnitine ranges, and thus decreased oxidation of fatty acid within the mitochondria. Muscle synthesized on the protein and launched as such upon protein degradation; it’s discovered on proteins reminiscent of histones, calmodulin, myosin, cytochrome c. General, if you happen to lower vitamin C, you should have a lower in carnitine and subsequently a lower in beta-oxidation and thus the muscle should depend on different vitality types as a result of it’s not in a position to switch fatty acids effectively into the mitochondria.

Deficiency Scurvy is the title given to somebody who severely lacks vitamin C. Acknowledgement of scurvy signs dates again to the Papryrus of Elber, Egypt, in roughly 1550 BC. Documentation of scurvy signs additionally exist in the course of the explorations of Jacques Cartier in 1535. It was presently that Native People taught Cartier to make use of white cedar extract in deal with his sailors that had been dying from scurvy. On the time, nobody knew precisely what was the reason for this, till a British doctor determined to conduct a examine that offered a number of sailors with lime juice. Those that consumed the lime juice didn’t develop scurvy, thus giving them the nickname “limeys.” Finally the issue was remoted from the lime juice and located to be the 6-carbon glucose construction termed ascorbic acid (vitamin C).

Signs embrace microcytic anemia, hemorrhaging, bleeding gums, muscle mass start to degenerate, joint ache, and failure of wounds to heal. Vitamin C, although, is quickly reversible by taking average dosages of the vitamin.

Signs of scurvy: o Mushy bones (lack of collagen matrix, perhaps lack of sulfonation) o Gum bleeding, tooth loosening (lack of cell matrix) o Capillary bleeding (lack of extracellular matrix supporting capillaries) o Slowed wound therapeutic (relies on collagen and the extracellular matrix) o Coiled hair (modifications in collagen construction within the hair) o Psychosis, hysteria, despair (?? Lack of neurotransmitters??)

People are in danger for creating a vitamin C deficiency with an elevated consumption of steroid or fragrant medicine. These enhance the necessity for ascorbate to hydoxylate and take away the compounds from the physique. Examples of most of these medicine embrace: oral contraceptives, toxins, barbituates and stress-related glucocorticoids.

People who smoke cigarettes even have a excessive requirement for vitamin C. These people have a considerably decrease serum focus. That is believed to be because of the toxins within the smoke that promote harmful oxidation and free radical reactions within the lungs and physique; prevention and correction of those reactions depletes the physique of ascorbate. People who smoke are advisable to extend their ascorbate consumption to 100 mg/day.

Toxicity Regardless that vitamin C is a water soluble vitamin, supplementing with extreme vitamin C could be harmful. In sure people excessive doses may cause iron toxicity because of its mobilization impact.

Sources o citrus fruits (i.e. oranges, kiwi, and mangoes) o cabbage-type greens (i.e. spinach) o darkish inexperienced greens (i.e. broccoli, snow peas, and brussels sprouts) o papayas o cantaloupe o strawberries o purple bell peppers o lettuce o tomatoes o potatoes

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