Vitamin B6 Reduces Colon Cancer

Orthomolecular Medicine News Service, October 21, 2008

Vitamin B6 Reduces Colon Cancer
Intake is Often "Inadequate" Even When it Exceeds the RDA

(OMNS, October 21, 2008) A study of almost 5,000 persons has shown that consuming
more vitamin B6 means less colon cancer. (1) The researchers described the
connection as "moderately strong." Any nutrient that has a "moderately strong"
influence on reducing colon cancer risk is very important indeed. Almost 150,000
Americans are annually diagnosed with colon cancer; nearly 55,000 die every single
year. Other authors, reviewing previous studies, have said the same thing: B6
substantially reduces colon cancer risk. (2,3)

Many of us are not getting nearly enough B6 from our diets. The American Journal of
Clinical Nutrition (May, 2008) published a study of nearly 8,000 people showing that
B6 inadequacy is common throughout the United States. "Across the study population,"
the authors said, "we noticed participants with inadequate vitamin B6 status even
though they reported consuming more than the Recommended Daily Allowance of vitamin
B6, which is less than 2 milligrams per day." Three out of four women using oral
contraceptives are vitamin B6 deficient, unless they also take vitamin B6
supplements. Smokers and the elderly are also especially likely to be at risk.
Remarkably, even among people who take B6 supplements, one in ten is still B6
deficient. (4)

This indicates that we might better take more B6. But many won't. This is because
the public has been warned off of supplementing with this vitamin. So irrational is
this fear that, at one point, a so-called "Safe Upper Limit" for daily B6 intake was
set at only 10 mg. (6) That was only about six times the US RDA/DRI. Who set such a
"limit"? Not the voters, that's for sure. An unelected committee did it, one created
by the National Academy of Sciences, Institute of Medicine's Food and Nutrition
Board. (5) They have, in a manner of speaking, recently admitted that they were
wrong. The "Safe Upper Limit" is now 100 mg.

That is more like it, but still too low. Alan Gaby, M.D., in reviewing B6 toxicity,
wrote that adverse effects from B6 (pyridoxine) were occurring in people taking
"2,000 mg/day or more of pyridoxine, although some were taking only 500 mg/day.
There is a single case report of a neuropathy occurring in a person taking 200
mg/day of pyridoxine, but the reliability of that case report is unclear. The
individual in question was never examined, but was merely interviewed by telephone
after responding to a local television report that publicized pyridoxine-induced
neuropathy." Dr Gaby adds that there have been no reports of B6 side effects at
under 200 mg/day. (6)

Modern processed, low-nutrient diets are not providing anything close to 200
milligrams. In fact, they typically provide less that 1% of that amount. You can get
some B-6 from food, if you really like to eat whole grains, seeds and organ meats. A
goodly slice of beef liver contains a whopping 1.2 mg of B-6. Chicken liver is only
0.6 mg per serving, and most other foods contain less. Avocados (0.5 mg each) and
bananas (0.7 mg each) lead the pyridoxine league for fruits. Potatoes (0.7 mg each)
and nuts (especially filberts, peanuts and walnuts) are fairly good vegetable

But people are not eating nuts, seeds, vegetables, and liver. What they are eating
is way too many nutrient-poor junk foods. Our diets are low in B6, yet B6 reduces
risk of colon cancer. Clearly supplementation is the way to go.


(1) Theodoratou E, Farrington SM, Tenesa A et al. Dietary vitamin B6 intake and the
risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev. 2008 Jan;17(1):171-82.

(2) Matsubara K, Komatsu S, Oka T, Kato N. Vitamin B6-mediated suppression of colon
tumorigenesis, cell proliferation, and angiogenesis (review). J Nutr Biochem. 2003
May;14(5):246-50. See also: Komatsu S, Yanaka N, Matsubara K, Kato N. Antitumor
effect of vitamin B6 and its mechanisms. Biochim Biophys Acta. 2003 Apr
11;1647(1-2):127-30. "Epidemiological studies have reported an inverse association
between vitamin B(6) intake and colon cancer risk."

(3) Zhang SM et al. Folate, vitamin B6, multivitamin supplements, and colorectal
cancer risk in women. Am J Epidemiol. 2006 January 15; 163(2): 108-115. .

(4) Morris MS, Picciano MF, Jacques PF, Selhub J. Plasma pyridoxal 5'-phosphate in
the US population: the National Health and Nutrition Examination Survey, 2003-2004.
Am J Clin Nutr. 2008 May;87(5):1446-54. See also:


(6) Gaby AR. "Safe Upper Limits" for nutritional supplements: one giant step
backward. J Orthomolecular Med, 2003, Vol 18, No 3&4, p 126-130. and

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