Should you stop taking your multivitamin?

November 3rd, 2011 By Steven Knope, MD

The Myth of the Missing Substance

“Early to bed, early to rise, take multivitamins and you’re more likely to die.”

Okay, so I changed this old chestnut a bit to get your attention. However, as many of you have now read, a recently published study in the Archives of Internal Medicine showed that adult women who took multivitamins had a higher mortality rate than those who did not. Before you conclude that this finding was unrelated to the vitamins, consider this: The women who took vitamins were healthier to start with than those women who did not take vitamins. The vitamin-takers were leaner, had lower levels of diabetes and hypertension, and ate more fruits and veggies. Yet after 20 years, the women who took multivitamins died at a higher rate.

For those who would like a nice, readable summary of the findings of this study, I refer you to this Time Magazine online article.

Why do people take vitamins?
We start from a logical enough theory, which goes something like this: Nobody eats a perfect diet. All of us are probably deficient in some nutrients and vitamins. Therefore, just to be on the safe side, it is better to take vitamins and supplements, just to make sure that we get everything that we need. Besides, even if we don’t need all of those vitamins and supplements, our bodies will just pee out what we don’t need. Gee whiz (no pun intended), we’ve all seen the pretty colors in our own vitamin-filled urine, so what’s the big deal? What can it hurt?

Pearl One.
There is no critical substance missing from your body! There is a myth out there, propagated by vitamin and supplement producers, that there is something important missing from your body. I call this, “The Myth of the Missing Substance.” If only you had more magnesium, ginkgo, CoQ10, folic acid, vitamin C, copper or zinc, your body would be restored to optimal health. This is baloney. Unless you have a documented vitamin deficiency, with good clinical evidence that replacing that vitamin will benefit your health, there is nothing “natural” or “healthy” about taking vitamins in pill form. Get your vitamins and nutrients from your diet.

Pearl Two.
It is the role of science to test hypotheses before they are put into clinical practice. The problem with beautiful theories is that they are often spoiled by ugly facts. For example, “Estrogen replacement reduces the risk of heart disease.” It does not! We told women to take estrogen from horse urine (Premarin) for 30 years before we tested this hypothesis and found out that it was false. As human beings, we hold many beliefs. Some beliefs are helpful; some are harmful. In addition, we all have bias. Unless we are willing to test our beliefs, we are destined to be imprisoned by those theories that are detrimental to us. In medicine, ignorance is not bliss.

Let’s take a look at the increase in mortality associated with specific vitamins noted in the Archives of Internal Medicine study, nicely outlined in the Time summary:

  • Vitamin B: 10% higher risk of death, compared with nonusers
  • Folic acid: 15%
  • Iron: 10%
  • Magnesium: 8%
  • Zinc: 8%
  • Copper: 45%

Pearl Three.
Due to a congressional act called the Dietary Supplement and Health Education Act (DSHEA), the manufacturers of vitamins and supplements have no obligation to prove the purported benefits of their products. Even worse, under DSHEA, the manufacturers of supplements have no obligation to even guarantee that what they put on the label is contained within the pill in the bottle. The FDA does not regulate vitamins & supplements.

My Experience with the Vitamin/Supplement Controversy: I have been on the receiving end of much criticism over the past 15 years for my public stance against the untested use of vitamins and supplements. I’ve debated Dr. Andrew Weil on PBS television on this issue and have received a fair amount of amusing hate-mail from those who buy his products. However, there are now numerous studies which have documented the absence of any benefit from multivitamins, even when used by debilitated nursing home patients who eat a poor diet. Supplemental antioxidants, such as carotene and folic acid, have been shown to increase cancer deaths. Selenium has not been shown to prevent prostate cancer. Vitamin C does not prevent colds. Vitamin E does not lower the death rates from heart disease and stroke and has recently been shown to increase the risk of prostate cancer.

Vitamins as Religion: In my experience, the strongly held belief that taking vitamins is essential for health often borders on the religious. Telling someone that they should not take their vitamins and supplements is viewed as blasphemy; and the vitamin companies know this.

To illustrate just how wedded people are to the idea of taking vitamins — and how immune many are to examining objective data — I will end with a quote published in the Wall Street Journal from Joseph Fortunato, chief executive of the supplement retailer, GNC Corporation, during a recent third-quarter company conference call: “The thing you do with [reports of studies] is just ride them out, and literally we see no impact on our business.”

Read: Is This the End of Popping Vitamins? from The Wall Street Journal online.


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