 Background
Most animals can manufacture their own Vitamin C, however humans have lost this ability over the course of evolution. This means that we must obtain our Vitamin C requirements from dietary sources, chiefly fresh fruits and vegetables.
From ancient times through the early nineteenth century, sailors and others deprived of fresh fruits and vegetables developed a disease called Scurvy. Scurvy is characterised by so-called scorbutic symptoms, which include poor wound healing, bleeding gums, bruising, and overall weakness. Scurvy was successfully treated with citrus fruit during the mid-1700s. In 1928, when Albert Szent-Gyorgyi isolated the active ingredient, he called it the "anti-scorbutic principle", or Ascorbic Acid.
More recently there have been hundreds of clinical studies on Vitamin C investigating its benefits for maintaining health and treating a range of diseases.
Recommended dietary intake and supplementation
The recommended dietary intakes (RDIs) from the National Health & Medical Research Council (NHMRC) for Vitamin C range from 25 - 40mg per day. These are designed to prevent deficiency states and do not recognise the significant health benefits that can be obtained by increasing intakes above these levels.
Vitamin C can be lost from food with storage and processing.
Infections and lifestyle choices such as smoking and drinking significantly reduce levels of vitamin C in the body.
The urinary excretion of Vitamin C from the body is increased during chemical, environmental, psychological and physiological stress.
During stress the level of Vitamin C present in the adrenal glands is substantially reduced.
Dietary sources
Dietary sources of Vitamin C include citrus fruits, broccoli, cabbage, capsicum, cauliflower and strawberries.
Therapeutic uses
Vitamin C plays a crucial role in a myriad of biochemical processes within the body.
It is a powerful antioxidant that is effective both inside and outside of cells, that protects against cellular damage from free radicals contained in environmental pollutants.
It plays an important role in the manufacture of collagen, a key protein in our connective tissues, cartilage, and tendons, and can assist in the healing of wounds and the maintenance of the health of the gums and capillaries.
It increases the absorption of non-heme iron (cereals and vegetables).
It activates glutathione peroxidase, the key liver detoxification enzyme, increasing its rate of synthesis and helping to protect the liver from free radical damage.
It is important for supporting and enhancing healthy adrenal gland function and the manufacture of adrenal hormones.
It is an important nutrient in bone metabolism, especially in the synthesis of collagen that forms the structural framework of bones.
It assists in maintaining a healthy immune system.
Clinical studies have demonstrated that Vitamin C can:
- shorten the duration and lessen the symptoms of colds;
- reduce the risk of developing cataracts and macular degeneration in older people;
- result in improved maintenance of bone mineral density in menopausal women;
- reduce the risk of developing preeclampsia, a complication of pregnancy;
- reduce the risk of excessive bruising in individuals with marginal deficiency of the vitamin.
Therapeutic dosage
Clinical studies using a dose of 1g of Vitamin C per day have been shown to be effective in reducing the severity and duration of the symptoms of colds.
Storage
Keep in a safe place out of the reach of children and where the temperature stays below 30°C.
Pack size
100 tablets
Contraindications
Some individuals may develop diarrhoea, however this usually resolves itself with continued use gradually build up again.
Individuals with a history of kidney stones and those who have a defect in Vitamin C or Oxalate metabolism should consult their health care professional before using Vitamin C supplements.
Individuals with diseases that result in accumulation of iron in the body, such as Haemochromatosis, should consult their health care professional before using Vitamin C supplements.
Drug interactions
Many common OTC and prescription medicines, such as Aspirin and the contraceptive pill, can affect levels of Vitamin C in the body.
High doses of Vitamin C may impair copper absorption.
References
NHMRC, Recommended Dietary Intakes for Use in Australia. 1991
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Hankinson SE, Stampfer MJ, Seddon JM, et al. Nutrient Intake and Cataract Extraction in Women: A Prospective Study. BMJ. 1992; 305: 335-339.
Jacques PF, Taylor A, Hankinson SE, et al. Long-term Vitamin C Supplement Use and Prevalence of Early Age Related Lens Opacities. Am J Clin Nutr. 1997; 66: 911-916.
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Chappell LC, Seed PT, Briley AL, et al. Effect of Antioxidants on the Occurrence of Pre-eclampsia in Women at Increased Risk: A Randomised Trial. Lancet. 1999; 354: 810-816.
Schorah CJ, Tormey WP, Brooks GH, et al. The Effect of Vitamin C Supplements on Body Weight, Serum Proteins, and General Health of an Elderly Population. Am J Clin Nutr. 1981; 34: 871-876.
Lykkesfeldt J, Christen S, Wallock LM, et al. Ascorbate is Depleted by Smoking and Repleted by Moderate Supplementation: A Study in Male Smokers and Non-smokers with Matched Dietary Antioxidant Intakes. Am J Clin Nutr. 2000; 71: 530-536.
Coffey G, Wilson SW. Letter: Ascorbic Acid Deficiency and Aspirin Induced Haematemesis. Br Med J. 1975; 1: 208.
Das N, Nebioglu S. Vitamin C Aspirin Interactions in Laboratory Animals. J Clin Pharm Ther. 1992; 17: 343-346.
Molloy TP, Wilson CW. Protein Binding of Ascorbic Acid. Interaction with Acetylsalicylic acid. Int J Vit Nutr Res. 1980; 50: 387-392.
Rivers JM, Devine MM. Plasma Ascorbic Acid Concentrations and Oral Contraceptives. Am J Clin Nutr. 1972; 25: 684-689.
Webb JL. Nutritional Effects of Oral Contraceptive Use: A Review. J Reprod Med. 1980; 25: 150-156.
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