Vitamins and Cancer
Vitamins are under the auspices of the FDA, so the standard dosage contained in commercial products can be considered safe under most conditions.
Vitamin supplements have been produced and sold for many years, so potential toxicity that can occur with certain nutrients is well-known and quality control measures are standardized.
Because diet may be compromised during cancer treatment, standard supplementation may help strengthen the body's immunity.
You may have seen reports that "mega" doses of certain vitamins may "cure" cancer and other diseases.
By megadoses we mean vitamins taken in amounts well above the Recommended Daily Allowance (RDA).
For example, some patients have read that vitamins C and E have properties that may protect against cancer.
These two vitamins are among a group of nutrients known as antioxidants, which means that they protect cells from damage caused by free radicals, which are unstable molecules that form through a process known as oxidation.
Antioxidants are nutrients that neutralize the harmful effects of free radicals.
It is true that both nutrients are essential for a healthful diet.
Vitamin E is found in green leafy vegetables, whole grains, nuts, eggs, and plant oils.
Vitamin C is found in citrus fruits, melons, berries, tomatoes, potatoes, and many other vegetables.
Several studies initiated in the 1970s and 1980s have shown that high (upward of 1,000-2,000 mg) doses of vitamin C are of no benefit to cancer patients.
In addition, no evidence exists that high doses are needed to enhance the effects of the immune system.
Vitamin E has been studied in male smokers and, like vitamin C, it showed no effect on reducing lung cancer risk.
Some oncologists have concerns that high doses of vitamins E or C may lessen the effects of radiation or chemotherapy by protecting the cancer cells along with the normal cells.
This is probably unlikely given the relative potency of their antioxidant effect.
However, it is important to let your doctor know about any supplements you are taking.
Vitamin E in doses of 400-800 IU may cause easy bruising because of its effect on platelet (the clot-forming element in the blood) function.
In addition, be especially careful if you are taking blood thinners such as Coumadin, or anti-inflammatory drugs, because of the possibility of increased bleeding tendencies.
Vitamin E in doses higher than 800 IU may have side effects such as fatigue, dizziness, headache, blurred vision, or rash.
Do not take vitamin C if you have a history of kidney stones; other possible side effects of higher doses of vitamin C include nausea, diarrhea, stomach cramps, and low blood sugar.
The daily recommended dose is 75-125 mg a day.
The upper limit on tolerable doses is 2,000 mg.
In addition, vitamin C given intravenously or in high doses (more than 2,000 mg) may be dangerous.
Some studies suggest that folate (a B vitamin) and calcium may have a possible protective effect against colon cancer.
These nutrients have other health benefits, too.
For example, calcium is especially important in maintaining bone density and preventing osteoporosis, which is why more of the mineral is recommended for women after menopause.
However, these nutrients are known to be safe only in standard doses, those in line with the RDA established for each.
A diet rich in fruits and vegetables is considered health-building because overall, these foods contain several essential nutrients, including the B-vitamin complex.
So, without singling out any particular nutrient, the general advice to eat fruits and vegetables remains sound.
In general, while there is no evidence that vitamins can cure cancer, a multivitamin with folate and enough daily calcium to maintain healthy bones is important for a healthful lifestyle.
Consult a nutritionist or dietician if you have questions about nutritional supplements and diet.
Vitamin supplements have been produced and sold for many years, so potential toxicity that can occur with certain nutrients is well-known and quality control measures are standardized.
Because diet may be compromised during cancer treatment, standard supplementation may help strengthen the body's immunity.
You may have seen reports that "mega" doses of certain vitamins may "cure" cancer and other diseases.
By megadoses we mean vitamins taken in amounts well above the Recommended Daily Allowance (RDA).
For example, some patients have read that vitamins C and E have properties that may protect against cancer.
These two vitamins are among a group of nutrients known as antioxidants, which means that they protect cells from damage caused by free radicals, which are unstable molecules that form through a process known as oxidation.
Antioxidants are nutrients that neutralize the harmful effects of free radicals.
It is true that both nutrients are essential for a healthful diet.
Vitamin E is found in green leafy vegetables, whole grains, nuts, eggs, and plant oils.
Vitamin C is found in citrus fruits, melons, berries, tomatoes, potatoes, and many other vegetables.
Several studies initiated in the 1970s and 1980s have shown that high (upward of 1,000-2,000 mg) doses of vitamin C are of no benefit to cancer patients.
In addition, no evidence exists that high doses are needed to enhance the effects of the immune system.
Vitamin E has been studied in male smokers and, like vitamin C, it showed no effect on reducing lung cancer risk.
Some oncologists have concerns that high doses of vitamins E or C may lessen the effects of radiation or chemotherapy by protecting the cancer cells along with the normal cells.
This is probably unlikely given the relative potency of their antioxidant effect.
However, it is important to let your doctor know about any supplements you are taking.
Vitamin E in doses of 400-800 IU may cause easy bruising because of its effect on platelet (the clot-forming element in the blood) function.
In addition, be especially careful if you are taking blood thinners such as Coumadin, or anti-inflammatory drugs, because of the possibility of increased bleeding tendencies.
Vitamin E in doses higher than 800 IU may have side effects such as fatigue, dizziness, headache, blurred vision, or rash.
Do not take vitamin C if you have a history of kidney stones; other possible side effects of higher doses of vitamin C include nausea, diarrhea, stomach cramps, and low blood sugar.
The daily recommended dose is 75-125 mg a day.
The upper limit on tolerable doses is 2,000 mg.
In addition, vitamin C given intravenously or in high doses (more than 2,000 mg) may be dangerous.
Some studies suggest that folate (a B vitamin) and calcium may have a possible protective effect against colon cancer.
These nutrients have other health benefits, too.
For example, calcium is especially important in maintaining bone density and preventing osteoporosis, which is why more of the mineral is recommended for women after menopause.
However, these nutrients are known to be safe only in standard doses, those in line with the RDA established for each.
A diet rich in fruits and vegetables is considered health-building because overall, these foods contain several essential nutrients, including the B-vitamin complex.
So, without singling out any particular nutrient, the general advice to eat fruits and vegetables remains sound.
In general, while there is no evidence that vitamins can cure cancer, a multivitamin with folate and enough daily calcium to maintain healthy bones is important for a healthful lifestyle.
Consult a nutritionist or dietician if you have questions about nutritional supplements and diet.
