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PROMOTES Antioxidant Function Immune Function Normal Interferon Levels Adrenal Function Thyroid Function Wound Healing: burns, surgical, etc Asthma Stability Diabetes Stability Iron Absorption Tissue Formation Work Productivity
PROTECTS AGAINST Respiratory Infections Viral Infections Flu Inflammation in General Cardiovascular Inflammation Fatigue Diminished Vision Sick Days
Daily intake of 300mg to 1000mg, at least half from supplements extended the life of men by 5 to 6 years and of women by 2 years according to research done by UCLA's James Enstrom. Smokers need 6 times more than nonsmokers. One puff of a cigarette can deplete vitamin C levels by 50%.
Overview Ascorbic acid, vitamin C, was first isolated from porcine adrenal glands in 1928 by Albert Szent-Gyorgyi. He called it hexuronic acid. It's complete molecular structure was described in 1933. The name was changed to ascorbic acid at this point. Ascorbic is derived from Latin scorbutus meaning scurvy and "A" meaning "not", thus translating to mean, "without scurvy". Scurvy is the oldest known nutritional deficiency disease. Vitamin C was found to be antiscorbutic, curing this hemorrhagic and tissue destroying illness.
Vitamin C is a water soluble vitamin that is absorbed from the small intestines. Human beings cannot produce vitamin C and are dependent on dietary sources or supplements as the source. It is utilized in varying concentrations throughout the body, the highest being the adrenal glands.
In nature there are two forms, the reduced form, L-ascorbic acid and the more active and oxidized form, L- **dhydroascorbic** acid. They have reversible equilibrium being able to convert back and forth to each other and both forms are bioavailable and absorbed.
Research over the later half of the twentieth and on into the twenty first century has substantiated and sustained support for the vital importance of this micronutrient.
Primary deficiency in adults is most frequently due to dietary deficiencies, either prescribed like the "ulcer diet" or more commonly, self imposed. Gastrointestinal disease, particularly inflammatory bowel disease like Crohn's disease, will interfere with absorption and lower concentrations. Pregnancy, lactation and hyperthyroid states will increase the physiological demand for vitamin C. Acute and chronic inflammatory disease in general, burns and surgery will likely significantly increase the amounts required for proper healing and concomitant ongoing normal bodily function. Besides physical stress, emotional stress tends to deplete stores of vitamin C quickly.
Deficiency symptoms include: -Anemia -Capillary fragility -Easy bruising -Gums that bleed easily -Hemorrhage -Muscular weakness -Poor wound healing -Poor appetite and growth -Swollen and tender joints
Severe deficiency results in scurvy both acute and chronic (see overview). This is a defect in the cementing substances in the cells of the connective tissues, bones, blood vessels and tooth dentin. This results in weakened capillaries that spontaneously disrupt and defects in the bone, bony structures and the teeth. Wounds heal poorly and are easily disrupted.
Scurvy is rarely diagnosed in the U.S. although more mild chronic forms are probably not recognized. Those most susceptible include alcoholics, the elderly on diets low in fresh fruits and vegetables with no supplementation, and infants fed only cow's milk with no prescribed liquid vitamins. I have diagnosed scurvy in 2 patients that admitted to me that there were no fruits or vegetables in their diet. It is estimated that 20% of healthy elderly and up to 95% of institutionalized elderly are deficient. As much as 75% of those in cancer therapy show low concentrations, a population that should supplement.
Nicotine depletes vitamin C, so smokers, another thing to beware.
Aspirin is probably the most widely used drug that will deplete vitamin C even at low doses. Oral contraceptive drugs and certain hormone replacement medications have been demonstrated to decrease concentration levels. All steroids can deplete vitamin C.
See DRUG DEPLETION TABLE for specific drug information.
Heat in cooking can destroy vitamin C.
FRESH FRUITS especially: -cantaloupe -citrus -currants -guava -strawberries
FRESH VEGETABLES especially: -asparagus -broccoli -Brussels sprouts -cabbage -collard greens -green peppers -lettuce -peas -tomatoes
Some fortified cereals
Vitamin C will readily give up an electron thus serving as an electron donor. This is it's action as an antioxidant able to neutralize free radicals. It reduces a number of oxidizing agents in the body.
It is vital in it's effects on lipids, particularly low density lipoproteins, the "bad" cholesterol. It helps keep LDL from becoming oxidized and more dangerous.
Vitamin C is essential in collagen formation. Collagen is the most abundant protein in the body, comprising approximately 30% of the total protein in the body. Collagen is necessary to maintain the integrity of skin, connective tissue, bone tissue, blood vessels and tooth dentin.
It is essential for wound healing and recovery from burns. It participates in oxidation-reduction reactions functioning as a redox system in the cell.
Vitamin C is involved in tyrosine and phenalalanine metabolism, overall energy production, reduction and storage of iron and the activation of folic acid. It is essential in the formation or synthesis of serotonin, norepinephphrine, thyroxine and some of the corticosteroids.
-Antioxidant Effect: Vitamin C donates hydrogen atoms from its two hydroxyl (OH) positions to neutralize free radicals. Because it is water soluble, it provides this protection in all body fluids.
-Antihistamine Effect: Vitamin C has a very mild antihistamine action as it inhibits the release and promotes the degradation of histamine. It can help block allergic responses and bronchial spasms in asthmatics.
-Antiviral Effect: At high doses, vitamin C stimulates the production of interferons, the proteins that can protect cells against viral attacks. In this way it may reduce the severity of symptoms associated with the common cold, herpes, and perhaps some other viruses.
-Anticarcinogenic Effect: Vitamin C prevents the formation of nitrosamines and can inhibit hyaluronidase, an enzyme found in malignant tumors. It stimulates the production of phagocytic leukocytes, the white blood cells (WBCs) which can engulf and destroy cancer cells. In studies, plasma concentrations of Vitamin C are inversely correlated with the incidence of GI and cervical cancers and may prevent the formation of bladder tumors. The prevention of free radical damage may also play a role in cancer prevention.
-Anti-stress Effect: Vitamin C helps the body cope with all types of stress. The body's main stress response hormones in the adrenal glands require vitamin C. It can help protect the immune system under stress by increasing levels of antibodies (IgA, IgG, IgM) required for fighting infections, increasing interferon, prompting WBC production and modulating prostaglandin synthesis.
-Detoxification: Vitamin C can have detoxifying effects on some heavy metals, including mercury, lead, cadmium, and nickel.
-Regeneration: Vitamin C can regenerate alpha tocopherol one of the eight main members of the vitamin E "family". It also has been associated with higher concentrations of high density lipoprotein (HDL), the "good cholesterol".
Regulations from the U.S. Food and Drug Administration (FDA) require that any vitamin C sold as a dietary supplement in the United States contain at least 100% of its labeled amount. The United States Pharmacopoeia (USP) requires that products contain 90% to 110% of the claimed amount and that they meet certain specifications for disintegration and purity. Unfortunately, the FDA doesn't test for quality before sales, and products stating that they meet the USP standards don't always do so.
The National Institute of Health studied vitamin C excretion in individuals who were at a steady state concentration of vitamin C meaning having adequate amounts in their body already. This study was done in 1996. The finding revealed that at a dose of less than 100mg no urine excretion of the vitamin was detected. At 100mg a day, approximately 25% of the dose was excreted and at 200mg a day about 50% was excreted. At doses such a 500 - 1250mg per day only part of the ingested amount was absorbed but almost the entire absorbed amount was excreted. The data from this study shows that at steady-state doses of vitamin C greater than 500mg a day have little impact on body stores with a threshold dose of 100mg a day and the threshold plasma concentration for excretion to be 55 to 60 micro mol per liter. Because vitamin C saturation has no apparent adverse consequences, the ideal amount to take daily for people who have vitamin C rich foods in their diets daily would be the amount that produces maximum saturation for beneficial biochemical functions that are vitamin C dependent such as wound healing, bone formation, carnitine synthesis for fatty acid metabolism and synthesis of some hormones.
Vitamin C may interfere with the absorption of the tricyclic class of antidepressant medication. It can alter the anticoagulation effect of warfarin, i.e. coumadin. One study suggests it may interfere with the effectiveness of statin type cholesterol lowering drugs. It may interfere with some diagnostic tests for cholesterol and blood sugar levels and for hidden blood in the stool.
Because vitamin C enhances iron storage in the body, people with disease that causes to much iron to be stored should be cautious with vitamin C supplementation.
Recommended Dietary Allowance: The RDA -recommended dietary allowance- for vitamin C is 60 mg a day. The scientific literature reflects pharmacological dosages of vitamin C ranging from 500mg to 20 grams a day. The high doses were divided into 3 and 4 times a day dosing.
RDA/AI* (Adequate Intake)
AGE (YRS) AMOUNT in milligrams (mg) / day
Infants 0.0-0.5: 40 - 50* 0.5-1.0: 40 - 50*
Children 1-3: 15 - 25 4-8: 15 - 25
Males 9-13: 45 14-18: 75 19-30: 90 31-50: 90 51-70: 90 71+: 90
Females 9-13: 45 14-18: 65 19-30: 75 31-50: 75 51-70: 75 71+: 75
Pregnant >18yo: 85
Lactating >18yo: 120
Toxic Doses: Huge doses of vitamin C, >10 grams a day, has not been shown to consistently decrease onset of the common cold and may cause diarrhea from osmotic effects, predispose to urinary oxalate calculi (a type of kidney stone), and promote iron overload resulting in an actual increase of oxidative free radicals. |