A new patient said he had stopped taking vitamins and minerals because of an article I wrote saying they may increase cancers.

Indeed, an editorial in the March 18, 2009, Journal of the National Cancer Institute said, "The prospects for cancer prevention through micronutrient supplementation have never looked worse. Several large, randomized cancer prevention trials have recently reported no reduced risk from micronutrient supplementation, and the short report by Figueiredo et al. in this issue of the Journal adds to a growing body of evidence that micronutrient supplementation may be harmful." Jane Figueiredo of University of Southern California and others found that men taking 1 mg a day of folic acid rather than a fake placebo doubled their risk of prostate cancer.

And regarding colon cancer, an article in the June 6, 2007, Journal of the American Medical Association found that 1 mg a day of folic acid in folks who had had polyps in their large bowel actually increased by 67 percent pre-cancerous growths called advanced colorectal adenomas.

If you Google my name, you'll see why vitamins E, A, and beta-carotene may also be harmful. And in a case-control study in the July 2009 issue of Cancer Causes & Control, Boston University researchers found that men who took zinc, either alone or in a multivitamin, doubled their risk of prostate cancer. The only randomized study showing possible cancer reduction was one showing that 1,200 mg of calcium a day reduced recurrences of colorectal adenomas.

But whoa — don't vitamins reduce heart disease? Well just last month, the Cochrane group looked at studies of 24,210 subjects and found that lowering homocysteine levels with folic acid, B6 or B12 did not reduce heart attacks, strokes, or deaths.

But eating more fruits and leafy vegetables high in vitamins like folate, A and C reduces heart disease and cancers, so what gives? Per the editorial, it may not be the vitamins, but rather dozens of bioactive compounds like glucosinolates and cathechins that do us good. Randomly selecting a handful of vitamins and minerals under the assumption that they reduce cancers, then taking extra amounts of them is unnatural and may throw off the balance of what we get naturally in the correct proportions in foods, abnormally changing dozens of biochemical reactions in our cells and causing harm. Now younger women should take at least 0.4 milligrams of folic acid daily during and even before pregnancy to prevent birth defects. But forget the vitamin E and other stuff. I myself only take vitamin D 800 to 1,000 IU and calcium 1,200 mg a day.