What are the Key Functions of Vitamin C?
- This Vitamin is involved in a large number of biological processes, making it essential for health.
- It is used to create collagen in the body, a protein that makes the skin, joints and bones strong.
- Ascorbic acid plays a role in healing wounds within the body.
- The body utilizes ascorbic acid in the immune system by maintaining activity of the white blood cells.
Vitamin C is a water-soluble vitamin that has a number of biological functions:
Acting as an antioxidant, one of it’s important functions is to protect LDL (a.k.a. bad cholesterol) cholesterol from oxidative damage.
Only when LDL is damaged does cholesterol appear to lead to heart disease.
The antioxidant properties are thought to protect smokers, as well as people exposed to second hand smoke, from the harmful effects of free radicals.
Ascorbic acid may also protect against heart disease by reducing the stiffness of arteries and the tendency of platelets to clump together.
Ascorbic acid is needed to make collagen, the “glue” that strengthens many parts of the body, such as muscles and blood vessels.
This vitamin also plays important roles in wound healing and as a natural antihistamine and also helps to fight viruses and to detoxify alcohol and other substances.
Vitamin C improves nitric oxide activity. Nitric oxide is needed for the dilation of blood vessels, potentially important in lowering blood pressure and preventing spasms of arteries in the heart that might otherwise lead to heart attacks.
Vitamin C has reversed dysfunction of cells lining blood vessels. The normalization of the functioning of these cells may be linked to prevention of heart disease.
Evidence indicates that levels of this vitamin in the eye decrease with age and that supplementing prevents this decrease, possibly leading to a lower risk of developing cataracts.
Vitamin C has been reported to reduce activity of the enzyme, aldose reductase, in people. Aldose reductase is the enzyme responsible for accumulation of sorbitol in eyes, nerves, and kidneys of people with diabetes.
This accumulation is believed to be responsible for deterioration of these parts of the body associated with diabetes.
Vitamin C may help protect the body against accumulation or retention of the toxic mineral, lead.
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What are the Best Food Sources of Vitamin C?
Citrus fruit, green peppers, sweet and hot peppers, potatoes, spinach, parsley, cabbage, broccoli, Brussels sprouts, rose hips, black currants and other berries, tomatoes, horseradish, watercress are good sources of vit-C.
Water, cooking, heat and light all reduce the levels of this vitamin available in food sources. Vegetables begin to lose ascorbic acid as soon as they are cut.
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Who would benefit from Vitamin C supplementation?
The following people may benefit from taking adequate or slightly higher than daily recommendations of this supplement.
- those who consume alcohol regularly,
- people taking medications regularly,
- and people who suffer from stress regularly
Although scurvy (severe Vitamin C deficiency) is uncommon in Western societies, many doctors believe that most people consume less than optimal amounts.
Fatigue, easy bruising, and bleeding gums are early signs of deficiency that occur long before frank scurvy develops. Smokers require a higher daily intake to maintain normal ascorbic acid levels.
Women with preeclampsia have been found to have lower blood levels of ascorbic acid than women without the condition which could lead to an increased risk of gallstones.
People with kidney failure have an increased risk of vit-C deficiency.
However, people with kidney failure should take vit-C only under the supervision of a doctor.
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When to use Vitamin C supplementation?
This supplement has been used in connection with the following conditions:
Anemia (if deficient)
Athletic performance (if deficient, or to reduce pain and speed up muscle strength recovery after intense exercise)
Bruising (for deficiency)
Common cold/sore throat
Gingivitis (periodontal disease) (for deficiency only)
Heart attack (for deficiency)
High cholesterol (protection of LDL cholesterol)
Infertility (male) (for sperm agglutination)
Reflex sympathetic dystrophy (prevention)
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How much Vitamin C is usually taken?
The recommended dietary allowance (RDA) for vitamin C in non smoking adults is 75 mg per day for women and 90 mg per day for men. For smokers, the RDAs are 110 mg per day for women and 125 mg per day for men.
Research has shown that, 500 mg of ascorbic acid per day for one year reduced the risk of developing reflex dystrophy (a painful nerve condition of the extremities), after a wrist fracture.
In a small, preliminary trial, ascorbic acid (500 mg twice daily) combined with rutoside (500 mg twice daily), a derivative of the flavonoid, rutin, produced marked improvement in three women with progressive pigmented purpura (PPP), a mild skin condition.
Cosmetic concerns lead people with PPP to seek treatment with a variety of drugs. The vit-C / rutoside combination represents a non-toxic alternative to these drug treatments, but larger, controlled trials are needed to confirm these preliminary results.
In terms of heart disease prevention, as little as 100–200 mg of ascorbic acid appears to be adequate. Although some doctors recommend 500–1,000 mg per day or more, additional research is needed to determine whether these larger amounts are necessary.
Some experts propose that adequate intake be considered 200 mg per day because of evidence that the cells of the human body do not take up any more vit-C when larger daily amounts are used.
Supplementing more, results in an excretion level virtually identical to intake, meaning that consuming more does not increase the amount that remains in the body.
Thus, the multiple gram amounts of ascorbic acid taken by many healthy people may be unnecessary.
The studies that ascertained approximately 120–200 mg daily of vit-C is correct for prevention purposes in healthy people have typically not investigated whether people suffering from various diseases can benefit from larger amounts.
A review of published trials found that amounts of 2 grams per day in children appear to be more effective than 1 gram per day in adults, suggesting that large intakes of ascorbic acid may be more effective than smaller amounts, at least for the common cold condition.
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What are the side effects of using Vitamin C?
Some people develop diarrhea after as little as a few grams of vitamin C per day, while others are not bothered by ten times this amount.
There is no strong scientific evidence to define and defend an upper tolerable limit for ascorbic acid.
Available research only concluded that high intakes (2–4 grams per day) are well-tolerated by healthy people. However, intake of large amounts of ascorbic acid can deplete the body of copper —an essential mineral. Copper is found in many multivitamin-mineral supplements.
Ascorbic acid increases the absorption of iron and should be avoided by people with iron overload diseases (e.g., hemochromatosis, hemosiderosis).
Vit-C helps to recycle the antioxidant, vitamin E.
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