Sources of Vitamin C

The richest natural sources are fruits and vegetables, and of those, the Kakadu plum and the camu camu fruit contain the highest concentration of the vitamin. It is also present in some cuts of meat, especially liver. Vitamin C is the most widely taken nutritional supplement and is available in a variety of forms, including tablets, drink mixes, crystals in capsules or naked crystals.

Vitamin C is absorbed by the intestines using a sodium-ion dependent channel. It is transported through the intestine via both glucose-sensitive and glucose-insensitive mechanisms. The presence of large quantities of sugar either in the intestines or in the blood can slow absorption.

Plant sources

While plants are generally a good source of vitamin C, the amount in foods of plant origin depends on: 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, and the method of preparation.

The following table is approximate and shows the relative abundance in different raw plant sources. As some plants were analyzed fresh while others were dried (thus, artifactually increasing concentration of individual constituents like vitamin C), the data are subject to potential variation and difficulties for comparison. The amount is given in milligrams per 100 grams of fruit or vegetable and is a rounded average from multiple authoritative sources:

Plant sourceAmount
(mg / 100g)
Kakadu plum3100
Camu Camu2800
Rose hip2000
Acerola1600
Seabuckthorn695
Jujube500
Indian gooseberry445
Baobab400
Blackcurrant200
Red pepper190
Parsley130
Guava100
Kiwifruit90
Broccoli90
Loganberry80
Redcurrant80
Brussels sprouts80
Wolfberry (Goji)73 †
Lychee70
Cloudberry60
Elderberry60
Persimmon60

† average of 3 sources; dried

Plant sourceAmount
(mg / 100g)
Papaya60
Strawberry60
Orange50
Lemon40
Melon, cantaloupe40
Cauliflower40
Garlic31
Grapefruit30
Raspberry30
Tangerine30
Mandarin orange30
Passion fruit30
Spinach30
Cabbage raw green30
Lime30
Mango28
Blackberry21
Potato20
Melon, honeydew20
Cranberry13
Tomato10
Blueberry10
Pineapple10
Pawpaw10
Plant sourceAmount
(mg / 100g)
Grape10
Apricot10
Plum10
Watermelon10
Banana9
Carrot9
Avocado8
Crabapple8
Persimmon - fresh7
Cherry7
Peach7
Apple6
Asparagus6
Beetroot5
Chokecherry5
Pear4
Lettuce4
Cucumber3
Eggplant2
Raisin2
Fig2
Bilberry1
Horned melon0.5
Medlar0.3

Animal sources

The overwhelming majority of species of animals and plants synthesise their own vitamin C, making some, but not all, animal products, sources of dietary vitamin C.

Vitamin C is most present in the liver and least present in the muscle. Since muscle provides the majority of meat consumed in the western human diet, animal products are not a reliable source of the vitamin. Vitamin C is present in mother's milk and, in lower amounts, in raw cow's milk, with pasteurized milk containing only trace amounts. All excess vitamin C is disposed of through the urinary system.

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

Animal SourceAmount
(mg / 100g)
Calf liver (raw)36
Beef liver (raw)31
Oysters (raw)30
Cod roe (fried)26
Pork liver (raw)23
Lamb brain (boiled)17
Chicken liver (fried)13
Animal SourceAmount
(mg / 100g)
Lamb liver (fried)12
Calf adrenals (raw)11
Lamb heart (roast)11
Lamb tongue (stewed)6
Human milk (fresh)4
Goat milk (fresh)2
Cow milk (fresh)2

Food preparation

Vitamin C chemically decomposes under certain conditions, many of which may occur during the cooking of food. Vitamin C concentrations in various food substances decrease with time in proportion to the temperature they are stored at and cooking can reduce the Vitamin C content of vegetables by around 60% possibly partly due to increased enzymatic destruction as it may be more significant at sub-boiling temperatures. Longer cooking times also add to this effect, as will copper food vessels, which catalyse the decomposition. Research has also shown that fresh-cut fruits don't lose significant nutrients when stored in the refrigerator for a few days.

Vitamin C supplements

Vitamin C is the most widely taken dietary supplement. It is available in many forms including caplets, tablets, capsules, drink mix packets, in multi-vitamin formulations, in multiple antioxidant formulations, and crystalline powder. Timed release versions are available, as are formulations containing bioflavonoids such as quercetin, hesperidin and rutin. Tablet and capsule sizes range from 25 mg to 1500 mg. Vitamin C (as ascorbic acid) crystals are typically available in bottles containing 300 g to 1 kg of powder (a teaspoon of vitamin C crystals equals 5,000 mg).

Artificial modes of 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 modern two-step fermentation process, 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.

Research is underway at the Scottish Crop Research Institute in the interest of creating a strain of yeast that can synthesise vitamin C in a single fermentation step from galactose, a technology expected to reduce manufacturing costs considerably. By 2008 only the DSM plant in Scotland remained operational outside the strong price competition from China. The world price of vitamin C rose sharply in 2008 partly as a result of rises in basic food prices but also in anticipation of a stoppage of the two Chinese plants, situated at Shijiazhuang near Beijing, as part of a general shutdown of polluting industry in China over the period of the Olympic games.

Food Fortification

Health Canada evaluated the effect of fortification of foods with abscorbate in the guidance document, Addition of Vitamins and Minerals to Food, 2005. Health Canada categorized abscorbate as a ‘Risk Category A nutrients’. This means it is either a nutrient for which an upper limit for intake is set but allows a wide margin of intake that has a narrow margin of safety but non-serious critical adverse effects. Health Canada recommended a minimum of 3 mg or 5 % of RDI in order for the food to claim to be a source of Vitamin C and maximum fortification of 12 mg (20 % of RDI) in order to be claimed "Excellent Source".

Further Reading


This article is licensed under the Creative Commons Attribution-ShareAlike License. It uses material from the Wikipedia article on "Vitamin C" All material adapted used from Wikipedia is available under the terms of the Creative Commons Attribution-ShareAlike License. Wikipedia® itself is a registered trademark of the Wikimedia Foundation, Inc.

Last Updated: Feb 1, 2011

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