Vitamin C

:This article is about the nutrient.

Sources

Plant sources

Citrus fruits (lime, lemon, orange, grapefruit), tomatoes, and potatoes are good common sources of vitamin C. Other foods that are good sources of vitamin C include papaya, broccoli, brussels sprouts, black currants, strawberries, cauliflower, spinach, cantaloupe, and kiwifruit. Also, cranberries and red peppers are good sources of the vitamin.

Related Topics:
Lime - Lemon - Orange - Grapefruit - Tomato - Potato - Papaya - Broccoli - Brussels sprout - Black currant - Strawberries - Cauliflower - Spinach - Cantaloupe - Kiwifruit

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The amount of vitamin C in foods of plant origin depends on:

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• the precise variety of the plant,
• the soil condition
• the climate in which it grew,
• the length of time since it was picked,
• the storage conditions,
• the method of preparation. Cooking in particular is often said to destroy vitamin C - but see the section on Food preparation.

The following table is approximate and shows the relative abundance in different raw plant sources. The amount is given in mg per 100 grams of fruit or vegetable:

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Animal sources

The overwhelming majority of species of animals and plants synthesise their own vitamin C. It is therefore not a vitamin for them. Synthesis is achieved through a sequence of 4 enzyme driven steps, which convert glucose to ascorbic acid. It is carried out either in the kidneys, in reptiles and birds, or the liver, in mammals and perching birds. The last enzyme in the process, l-gulonolactone oxidase, cannot be made by man because of a defective gene that he carries. The loss of an enzyme concerned with ascorbic acid synthesis has occurred quite frequently in evolution and has affected most fish, many birds; some bats, guinea pigs and most but not all primates, including Man. The mutations have not been lethal because ascorbic acid is so prevalent in the surrounding food sources.

Related Topics:
Enzyme - Glucose - Kidney - Reptiles - Birds - Liver - Mammals - Perching birds - Ascorbic acid - Evolution - Fish - Bird - Bat - Guinea pig - Primates - Mutation

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For example an adult goat will manufacture more than 13,000 mg of vitamin C per day in normal health and as much as 100,000 mg daily when faced with life-threatening disease, trauma or stress.

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Trauma or injury has been demonstrated to use up large quantities of vitamin C in animals and man.

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It was only realised in the 1920s that some cuts of meat and fish are also a source of vitamin C for humans. The muscle and fat which make up the modern western diet are however poor sources. As with fruit and vegetables cooking destroys the vitamin C content.

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The following table shows the relative abundance of vitamin C in various foods of animal origin, given in mg of vitamin C per 100 grams of food:

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Artificial chemical synthesis

Vitamin C is produced from glucose by two main routes. The Reichstein process developed in the 1930s uses a single pre-fermentation followed by a purely chemical route. The more modern Two-Step fermentation process was originally developed in China in the 1960s, uses additional fermentation to replace part of the later chemical stages. Both processes yield approximately 60% vitamin C from the glucose feed.

Related Topics:
Glucose - China

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In 1934, the Swiss pharmaceutical company Hoffmann-La Roche was the first to mass produce synthetic vitamin C, under the brand name of Redoxon.

Related Topics:
Hoffmann-La Roche - Redoxon

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Main producers today are BASF/Takeda, Roche, Merck and the China Pharmaceutical Group Ltd. of the People's Republic of China.

Related Topics:
BASF - Takeda - Roche - Merck - People's Republic of China

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