"Why is vitamin B6 so wonderful as a preventive-healthcare therapy?"
That question is posed by John M. Ellis, M.D., in his 1998 groundbreaking book titled "Vitamin B6 Therapy: Nature's Versatile Healer."
Dr. Ellis explains that B6 is vitally important because the body converts the vitamin into pyridoxal phosphate, a coenzyme that activates enzyme systems – the movers and shakers that trigger every activity in the body. Nearly 120 enzymes need B6 to function properly, and 19 out of your body's 20 amino acids require B6.
But even healthy people, both young and old, tend to be deficient in vitamin B6, according to Dr. Ellis. That's why he believes that B6 supplements must be added to a B6-rich diet in order to maintain sufficient amounts of the vitamin.
Your reward for making sure you get enough B6 can be summed up in two words: cancer prevention.
In the spring of 2005, Harvard Medical School published research that examined ten years of medical records from the Nurses' Health Study. Comparing cases of colorectal cancer against blood tests, researchers found that subjects with the highest B6 concentrations had a 44 percent lower risk of colorectal cancer and nearly a 60 percent lower risk of polyps compared to subjects with the lowest B6 levels.
Later in the year, another research team examined 360 subjects with polyps and 425 polyp-free subjects and found that a lower risk of colorectal polyps was linked to high intake of five key nutrients: folate, beta-carotene, and vitamins C, D, and B6.
Then, early in 2006, another Harvard study found a significant association between dietary intake of folate and vitamin B6 and a reduced risk of colorectal cancer.
And finally, late last year, Tufts University researchers reported that even a modest deficiency of key components in the B complex (including B6) increases colorectal cancer risk.
Ten years after the publication of "Vitamin B6 Therapy," Dr. Ellis would probably approve of the most recent B6 study, which examined both dietary and supplementary intake of the vitamin.
Researchers at Scotland's University of Edinburgh recruited more than 2,000 subjects with colorectal cancer, and about 2,700 healthy control subjects. When vitamin consumption was assessed for each subject, researchers found that high levels of B6 intake reduced colorectal cancer risk by more than 20 percent.
In addition, the Edinburgh team conducted a meta-analysis of colorectal cancer studies in which B6 was tested. The result: High B6 intake reduced colorectal cancer risk by nearly 20 percent. In this analysis, B6 protection against colorectal cancer was slightly higher among subjects over the age of 55.
Bananas and chicken breast have particularly high levels of vitamin B6. Red meat, fish, beans, fruits, vegetables, and leafy greens are also good sources.
As for supplementing, HSI Panelist Allan Spreen, M.D., recommends 100 mg of B6 daily, along with other B vitamins, of course, and magnesium. Dr. Spreen: "B6 is definitely more effective in the company of magnesium – they work together intimately in the body."
Talk to your doctor before supplementing with magnesium or vitamin B6, especially if you have Parkinson's disease. Evidence shows that high levels of B6 may reduce potency of levodopa, a Parkinson's medication. Note also that levodopa may contribute to B6 deficiency.