Ester C (Vitamin C)
Ascorbic acid
In most animals, the water soluble nutrient, ascorbic acid, is synthesised from glucose. In humans a genetic lesion prevents us from making it and diet is the sole source of this vitamin. As a cofactor for many enzyme systems, ascorbic acid is involved in the synthesis of collagen, carnitine, endocrine hormones, and neurotransmitters. Many of the symptoms of the vitamin C deficiency disease scurvy can be attributed to weakened collagen structures, including bruising, muscle weakness, gum deterioration, and poor wound healing.
ESTER-C
The body changes vitamin C into numerous metabolites that may have physiological actions that are different from those of vitamin C itself. And these metabolites - whether manufactured in the body or ingested along with supplemental vitamin C - may influence how the vitamin itself is transported and utilized. The level of these metabolites in the body may not rise significantly, however, until very large doses of vitamin C are ingested. Laboratory studies have shown that suggested the mechanism by which C metabolites, especially threonate, might cause increased blood levels of vitamin C. Dr. Anthony Verlangieri at the University of Mississippi used isolated cells in culture to model how vitamin C is utilized by various body tissues. They observed that exposing cells to calcium threonate increased the uptake of ascorbic acid by these cells (Fay & Verlangieri, 1991; Fay, 1992; Fay, Bush & Verlangieri, 1994).
- IMMUNE FUNCTION - Vitamin C is known to be a potent immune stimulating nutrient. It has been shown to inhibit viral replication and may reduce the severity of the common cold. A recent study of one hundred and sixty-eight volunteers were randomized to receive a placebo or a vitamin C supplement, two tablets daily, over a 60-day period. The results showed that vitamin C supplement may prevent the common cold and shorten the duration of symptoms. Volunteers were generally impressed by the protection afforded them during the winter months. Clinical assessment has demonstrated that 2000mg of vitamin C per day for two weeks reduced blood histamine concentrations by 30-40% in adult subjects. Some evidence suggests that vitamin C may augment natural killer cell activity, which is important for the protection of tumour development. Research has shown that supplementation with the Ester-C calcium ascorbate/threonate complex provides an effective way to build vitamin C reserves in the important immuno-competent cells of the blood; even when modest doses (one gram) of ascorbate are used (Hunt & Rice, 1995).
- ANTIOXIDANT PROTECTION - Vitamin C performs many functions that may offer protection against cancer, including acting as an antioxidant and protecting cellular structures, including DNA, from damage. Researchers from the National Institutes of Health (NIH) recommended a daily vitamin C intake of 100 mg to 200 mg to reduce the risk of certain cancers. In a review published in the Journal of the American Medical Association, the NIH group found that diets with 200 mg or more of vitamin C from fruits and vegetables were associated with a lower risk of cancers in the gastrointestinal tract and lungs.
- CARDIOVASCULAR PROTECTION - A high dietary intake of vitamin C has been shown to significantly reduce the risk of death from heart attacks and strokes in numerous population studies.
- SKIN HEALTH - Vitamin C is essential for the healthy production of collagen synthesis required for bone, skin, and tendon formation.
- DIABETES - Insulin is known to facilitate the transport of vitamin C into cells, and so most diabetics suffer from deficient intracellular ascorbate levels. Vitamin C also inhibits sorbitol accumulation, thus reducing the risk of oxidative damage to the retina (diabetic retinopathy). Up to 3000mg of vitamin C have been shown to be beneficial in diabetic complications, including retinopathy and neuropathy.
Dosage
One negative side-effect of continued large doses of usual forms of vitamin C is gastrointestinal discomfort and diarrhoea. These effects are due in large part to the acidity of ascorbic acid itself. As a mineral ascorbate, Ester-C circumvents many of these problems because it has a neutral pH. At the same time, this new process introduces an important metabolite of vitamin C so it is present along with ascorbate when the supplement is taken. A 1998 review of over 20 clinical papers, undertaken by one of the UK's leading experts on antioxidants - at Guy's Hospital - showed that vitamin C is safe at doses up to 6g per day (to date studies have extended for up to two years).
Potential applications
Histamine hyper-responsiveness in respiratory tract infections, allergic disorders, bronchial asthma, and ulcerative colitis. Common cold, the elderly, convalescence, high alcohol intake, stress, smokers (each cigarette destroys approximately 25mg of vitamin C), those exposed to excessive pollution, athletes, osteoporosis, wound healing, skin ulcers, pressure sores. Vitamin C has been found to be effective in treating male infertility. Helicobacter Pylori infection, a strong risk factor for gastric cancer, has shown to be reduced by vitamin C supplementation. Interestingly, vitamin C is needed for carnitine synthesis, an amino acid that transports fatty acids into the mitochondria of muscle tissue. Reduced carnitine status appears to be responsible for the marked fatigue and lassitude shown in vitamin C deficiency and early scurvy.
Known contraindications
Vitamin C is extremely safe in most individuals. Claims that high-dose vitamin C regimens may lead to rebound scurvy, erythrocyte haemolysis, and vitamin B12 deficiency do not withstand scientific scrutiny. Vitamin C supplementation may have adverse effects in thalassemia major, an iron-overload disorder. High dose vitamin C regimens may increase urinary excretion of oxalic and uric acid although epidemiological investigations do not support an association between vitamin C supplementation and kidney stones. Nausea, diarrhoea, and abdominal cramping are observed in a small percentage of subjects consuming over 3g vitamin C per day.
Interactions
Some medicines can be affected by vitamin C. Women on the contraceptive mini-pill should not take excessively large doses of vitamin C at the same time of day as this may reduce the pill's effectiveness. Upper safe level: 2000mg (long term usage); 3000mg (short term usage). Vitamin C has been consumed in doses exceeding the European RDA (60mg per day) for many years without evidence of harm. Non-heme (vegetarian) iron absorption from a single meal is enhanced 2-3 fold in the presence of 25mg-75mg vitamin C. Vitamin C potentiates vitamin E activity in cells by regenerating alpha-tocopherol from its oxidised derivative. Vitamin C has also been shown to raise glutathione concentrations by 50 per cent with 500mg of vitamin C per day.
Use in conjunction with
- Common cold - Echinacea or Astragalus, multi-phytonutrient complex, zinc complex.
- Cardiovascular protection - vitamin E, CoQ10, flax seed oil, hawthorn berry, multi-phytonutrient complex.
Note
During times of chemical, emotional, psychological, or physiological stress, vitamin C is excreted at a significantly increased rate. Thus a higher intake of vitamin C is required for immune protection when the body is under stress.
References
- Michael Murray. 1996. The Encyclopaedia of Nutritional Supplements. P. 44-53
- B. Bowman, R. Russell. 2001. Present Knowledge in Nutrition. P.156-163
- Van Straten M, Josling P. Herbal Health Centre, Battle, East Sussex, United Kingdom. Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled survey. Adv Ther 2002 May-Jun;19(3):151-9
© Cheryl Thallon at Viridian
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