Nathan
New member
Someone was asking about vitamin C and dosages and such so I thought I'd post this to explain how vit C helps with muscle growth and many other vital functions.
VITAMIN C
What it does in the body
Vitamin C is involved in hundreds of vital biological processes in the body.
Collagen and connective tissue
The main role of vitamin C is in the manufacture of collagen. This protein forms the basis of connective tissue, the most abundant tissue in the body, and acts as a cementing substance between cells. It helps
support and protect blood vessels, bones, joints, organs and muscles, and forms a sizable proportion of skin, tendons, the cornea of the eye, ligaments, cartilage, teeth and bone. Collagen forms a protective barrier against infection and disease, and promotes healing of wounds, fractures and bruises.
Immune system
Vitamin C is critical to immune function as it is involved in antibody production and white blood cell function and activity. Other functions include the production of interferon, an antiviral and anticancer substance. Vitamin C requirements are raised when the immune system is under stress.
Antioxidant properties
Vitamin C is a powerful water soluble antioxidant and plays a vital role in protecting against oxidative damage. It neutralizes potentially harmful reactions in the watery parts of the body, such as the blood and the fluid inside and surrounding cells. It also helps protect LDL cholesterol against free radical damage. This antioxidant action helps to protect against cancer, the effects of aging, heart disease, and an array of other health problems.
Hormones
Vitamin C is important in the synthesis of adrenal hormones and is depleted from the adrenal glands in times of stress.
Nervous system
Vitamin C plays a role in the manufacture of neurotransmitters. It is necessary for the conversion of tryptophan to serotonin, and of tyrosine to dopamine and adrenaline.
Other functions
Vitamin C is involved in the manufacture of carnitine, a substance necessary for the production of energy from fatty acids in cells, especially cardiac and skeletal muscle cells. Vitamin C is necessary for the activity of the enzyme system which metabolizes drugs in the body. It is also necessary for iron absorption and plays a role in the conversion of cholesterol to bile acids for excretion. Vitamin C may also affect prostaglandin metabolism.
Absorption and metabolism
Absorption of vitamin C occurs in the intestine. The amount absorbed depends on the dose as the absorption mechanism is saturable and any excess excreted in the urine in two to three hours. As vitamin C is water soluble, only a small amount (about 4 to 5 g) is stored in the body. Vitamin C levels in the body are regulated by absorption and kidney excretion mechanisms.
Dosage
Opinions vary widely as to the optimal dose of vitamin C. Linus Pauling, the Nobel Prize winner who studied the effects of large doses of vitamin C on the common cold, flu and cancer, recommended an optimum intake of between 2 g and 9 g per day. Many experts believe that 500 mg is ideal to meet body needs while others feel that 200 mg is adequate. Vitamin C needs vary with age, weight, activity, energy levels, general metabolism and state of health.
In order to maintain blood levels of vitamin C, it is best to take it in divided doses throughout the day. Taking vitamin C with food minimizes adverse effects on the digestive system.
A study reported in 1997 in the American Journal of Clinical Nutrition suggests that doses of vitamin C above 200 mg do not increase blood levels of the vitamin significantly and may be excreted. Researchers at the University of Tucson in Arizona, measured blood levels of vitamin C when the dose given was 200 mg and then again when 2500 mg was administered. They found negligible absorption increases between the lower and higher doses.
Doctors who practise orthomolecular medicine use megadose vitamin C therapy in times of specific illness, especially viral infections. They typically use 20 to 40 g daily, often intravenously. With oral doses, some doctors believe that the amount of vitamin C needed is related to the severity of the disease and increase the dose until ‘bowel tolerance’ is exceeded and diarrhea results.
Toxic effects of excess intake
Vitamin C is safe in relatively large doses but excessive intakes may cause diarrhea, nausea, stomach cramping, excess urination and skin rashes. There is the possibility of kidney stones in those with kidney
disease. These effects may occur when doses above 1 g are taken regularly. Chewable vitamin C may lead to tooth decay.
Large doses of vitamin C taken by pregnant women have caused ‘rebound scurvy’ in newborn babies whose intake returns to normal. It may be advisable to reduce vitamin C intake slowly after taking large
amounts.
Results of a study reported in 1998 in Nature Medicine suggest that vitamin C may cause cell damage in doses above 500 mg. The researchers gave daily doses of 500 mg of vitamin C to 30 healthy volunteers
and then assessed two indicators of oxidative damage in DNA from their blood cells. One of these indicators showed less oxidation in the volunteers, and the other indicator showed more oxidation than before they began taking the supplements. However, this study directly contradicts other studies and focuses only on a single biological marker that is not necessarily known to be a good indicator of oxidative stress.
High blood pressure
Vitamin C may also be of benefit in the treatment of mild high blood pressure, another risk factor for heart disease and stroke. Some research suggests that vitamin C may have beneficial effects in lowering high blood pressure. Vitamin C supplements improve abnormal artery lining function in hypertensive people.
Immunity
Vitamin C boosts immunity by increasing the production of B and T cells and other white blood cells, including those that destroy foreign micro-organisms. It also increases interferon levels and antibody responses and has antiviral and antibacterial effects. These effects lead to improved resistance against infections.
Vitamin C has been shown to help the immune system recover from exposure to toxic chemicals. In a 1997 study, researchers studied the effect of vitamin C on the function of several immune cells (natural killer, T and B cells) in patients who had been exposed to toxic chemicals. Fifty-five patients were given buffered vitamin C in water at a dosage of 60 mg per kg body weight (around 4g for the average man).
Twenty-four hours later, the researchers tested immune cell function. The results showed that natural killer cell activity was enhanced up to ten-fold in 78 per cent of patients. B and T cell function was restored to normal.
Exercise
Strenuous exercise appears to increase the levels of free radicals in the body, increasing the risk of disorders in which oxidative damage play a part. As an antioxidant, vitamin C may help to prevent this damage. In a 1997 study researchers examined the effects of supplements on oxidative stress in athletes. They found that exercise-induced oxidative stress was highest when those involved in the study did not supplement with vitamin C.
Cautions
There is some concern that large doses of vitamin C may cause kidney stones because part of the oxalate in calcium oxalate kidney stones comes from metabolized vitamin C. However, this is unlikely to happen in healthy people. It may be advisable for anyone suffering from recurrent kidney stones, kidney disease or who has a defect in vitamin C metabolism to keep their daily intake of vitamin C to around 100 mg.
VITAMIN C
What it does in the body
Vitamin C is involved in hundreds of vital biological processes in the body.
Collagen and connective tissue
The main role of vitamin C is in the manufacture of collagen. This protein forms the basis of connective tissue, the most abundant tissue in the body, and acts as a cementing substance between cells. It helps
support and protect blood vessels, bones, joints, organs and muscles, and forms a sizable proportion of skin, tendons, the cornea of the eye, ligaments, cartilage, teeth and bone. Collagen forms a protective barrier against infection and disease, and promotes healing of wounds, fractures and bruises.
Immune system
Vitamin C is critical to immune function as it is involved in antibody production and white blood cell function and activity. Other functions include the production of interferon, an antiviral and anticancer substance. Vitamin C requirements are raised when the immune system is under stress.
Antioxidant properties
Vitamin C is a powerful water soluble antioxidant and plays a vital role in protecting against oxidative damage. It neutralizes potentially harmful reactions in the watery parts of the body, such as the blood and the fluid inside and surrounding cells. It also helps protect LDL cholesterol against free radical damage. This antioxidant action helps to protect against cancer, the effects of aging, heart disease, and an array of other health problems.
Hormones
Vitamin C is important in the synthesis of adrenal hormones and is depleted from the adrenal glands in times of stress.
Nervous system
Vitamin C plays a role in the manufacture of neurotransmitters. It is necessary for the conversion of tryptophan to serotonin, and of tyrosine to dopamine and adrenaline.
Other functions
Vitamin C is involved in the manufacture of carnitine, a substance necessary for the production of energy from fatty acids in cells, especially cardiac and skeletal muscle cells. Vitamin C is necessary for the activity of the enzyme system which metabolizes drugs in the body. It is also necessary for iron absorption and plays a role in the conversion of cholesterol to bile acids for excretion. Vitamin C may also affect prostaglandin metabolism.
Absorption and metabolism
Absorption of vitamin C occurs in the intestine. The amount absorbed depends on the dose as the absorption mechanism is saturable and any excess excreted in the urine in two to three hours. As vitamin C is water soluble, only a small amount (about 4 to 5 g) is stored in the body. Vitamin C levels in the body are regulated by absorption and kidney excretion mechanisms.
Dosage
Opinions vary widely as to the optimal dose of vitamin C. Linus Pauling, the Nobel Prize winner who studied the effects of large doses of vitamin C on the common cold, flu and cancer, recommended an optimum intake of between 2 g and 9 g per day. Many experts believe that 500 mg is ideal to meet body needs while others feel that 200 mg is adequate. Vitamin C needs vary with age, weight, activity, energy levels, general metabolism and state of health.
In order to maintain blood levels of vitamin C, it is best to take it in divided doses throughout the day. Taking vitamin C with food minimizes adverse effects on the digestive system.
A study reported in 1997 in the American Journal of Clinical Nutrition suggests that doses of vitamin C above 200 mg do not increase blood levels of the vitamin significantly and may be excreted. Researchers at the University of Tucson in Arizona, measured blood levels of vitamin C when the dose given was 200 mg and then again when 2500 mg was administered. They found negligible absorption increases between the lower and higher doses.
Doctors who practise orthomolecular medicine use megadose vitamin C therapy in times of specific illness, especially viral infections. They typically use 20 to 40 g daily, often intravenously. With oral doses, some doctors believe that the amount of vitamin C needed is related to the severity of the disease and increase the dose until ‘bowel tolerance’ is exceeded and diarrhea results.
Toxic effects of excess intake
Vitamin C is safe in relatively large doses but excessive intakes may cause diarrhea, nausea, stomach cramping, excess urination and skin rashes. There is the possibility of kidney stones in those with kidney
disease. These effects may occur when doses above 1 g are taken regularly. Chewable vitamin C may lead to tooth decay.
Large doses of vitamin C taken by pregnant women have caused ‘rebound scurvy’ in newborn babies whose intake returns to normal. It may be advisable to reduce vitamin C intake slowly after taking large
amounts.
Results of a study reported in 1998 in Nature Medicine suggest that vitamin C may cause cell damage in doses above 500 mg. The researchers gave daily doses of 500 mg of vitamin C to 30 healthy volunteers
and then assessed two indicators of oxidative damage in DNA from their blood cells. One of these indicators showed less oxidation in the volunteers, and the other indicator showed more oxidation than before they began taking the supplements. However, this study directly contradicts other studies and focuses only on a single biological marker that is not necessarily known to be a good indicator of oxidative stress.
High blood pressure
Vitamin C may also be of benefit in the treatment of mild high blood pressure, another risk factor for heart disease and stroke. Some research suggests that vitamin C may have beneficial effects in lowering high blood pressure. Vitamin C supplements improve abnormal artery lining function in hypertensive people.
Immunity
Vitamin C boosts immunity by increasing the production of B and T cells and other white blood cells, including those that destroy foreign micro-organisms. It also increases interferon levels and antibody responses and has antiviral and antibacterial effects. These effects lead to improved resistance against infections.
Vitamin C has been shown to help the immune system recover from exposure to toxic chemicals. In a 1997 study, researchers studied the effect of vitamin C on the function of several immune cells (natural killer, T and B cells) in patients who had been exposed to toxic chemicals. Fifty-five patients were given buffered vitamin C in water at a dosage of 60 mg per kg body weight (around 4g for the average man).
Twenty-four hours later, the researchers tested immune cell function. The results showed that natural killer cell activity was enhanced up to ten-fold in 78 per cent of patients. B and T cell function was restored to normal.
Exercise
Strenuous exercise appears to increase the levels of free radicals in the body, increasing the risk of disorders in which oxidative damage play a part. As an antioxidant, vitamin C may help to prevent this damage. In a 1997 study researchers examined the effects of supplements on oxidative stress in athletes. They found that exercise-induced oxidative stress was highest when those involved in the study did not supplement with vitamin C.
Cautions
There is some concern that large doses of vitamin C may cause kidney stones because part of the oxalate in calcium oxalate kidney stones comes from metabolized vitamin C. However, this is unlikely to happen in healthy people. It may be advisable for anyone suffering from recurrent kidney stones, kidney disease or who has a defect in vitamin C metabolism to keep their daily intake of vitamin C to around 100 mg.