Food Data Chart - Vitamin C



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24: VITAMIN C

Probably the first disease to be recognized as being caused by a nutritional deficiency was scurvy, when it was found that certain foods could prevent the disease. Scurvy was described by the Egyptians and Creeks, but it was Bachstrom in Leiden in 1734 who maintained that it was due to a lack of fresh vegetables in the diet. In 1795, the British Admiralty adopted James Lind's recommendations for citrus fruit to prevent seaboard scuny and, thereafter, British sailors were nicknamed 'limeys'.

In scurvy, the connective tissues of the body are defective; the tissues are fragile, and bleeding occurs into the skin, from the gums and into deeper tissues. Wound healing is also poor. Changes in brain and nerve function occur, with mood and personality changes. Muscle weakness and proneness to infection may occur. Our bodies' ability to detoxify certain chemicals may also be reduced in scurvy. It seems likely that there may be lesser degrees of vitamin C deficiency than the extreme of scurvy.

Vitamin C (or ascorbic acid, as it is also called) can be lost from foods because of its water solubility, and sensitivity to heat, air or oxygen. The addition of alkalis, such as bicarbonate of soda, and the use of copper cookware can also destroy it.

People at risk from vitamin C deficiency include those who avoid fruit and vegetables, those with poor cooking practices (see Figure 31 and Processing Food - Cooking), the elderly, alcohol abusers and cigarette smokers.

VITAMIN C INTAKE

Recommendations about vitamin C intake were first concerned with the prevention of scurvy. Recommended intakes of about 30 milligrams per day do not usually 'saturate' the body tissues with vitamin C and, indeed, this may not be necessary. But to saturate body tissues, no more than 100 to 130 milligrams per day are required. With intakes above this, our bodies adapt by increasing breakdown of vitamin C or excreting it in the urine. From a mixed diet it would be difficult to have more than about 400 to 500 milligrams of vitamin C per day.

It has been suggested that daily intakes of vitamin C in excess of 500 milligrams may be of benefit. There is some evidence that amounts of this kind may reduce the symptoms of the common cold. This raises the question of non-nutritional or drug-like properties of the vitamin. The possible adverse effects must also be considered. These include:'rebound scurvy', which may occur if you are coming off high-dosage vitamin C; increased excretion of oxalic acid in the urine which may lead to 'stones' in the urinary tract; an increased absorption of iron in those susceptible to iron overload; increased absorption of toxic metals, such as mercury; and interactions with certain medications, for example warfarin, aspirin, antidepressants and the contraceptive pill.

VITAMIN C INTAKE

Recommended daily dietary intake of vitamin C:

AUSTRALIA milligrams U.S.A. milligrams

Infants:
Children:

Adult men:

Adult women:

Pregnancy (2nd and 3rd
trimesters)

Lactation:
30

30-50

30

30

60

60
35

45

60

60

80

100


	Water-Soluble Vitamins

	-	Vitamin B-1 (thiamin)
	-	Vitamin B-2 (riboflavin)
	-	Niacin
	-	Vitamin B-6
	-	Vitamin B-12 (cyano-cobalamin)
	-	Folacin
	-	Pantothenic acid
	-	Biotin
		Vitamin C