Since I am interested in vitamin research, I have a Google Alert with the term "vitamin." Every day I get an email from Google that lists everything that has been newly published on vitamins on the entire web. This is truly amazing because I remember back a long generation ago (in the 1980's) when an all-day effort at the medical library was required to retrieve a few relevant articles that were written, at best, the previous year. With the Internet and Google Alerts, I can review everything that is currently being published around the world on vitamins, every day, and it's delivered to me for free.

What I have found very interesting about these Google Alerts on vitamins is that there is a constant flow of conflicting research. Some days Vitamin E is heralded as a vitamin that can boost lifespan1, can enhance the immune system of seniors2, and can act as an effective anti-aging tool3. On another day, a sobering headline links the use of Vitamin E with higher overall death rates4. As a physician whose first axiom is to "do no harm," I am quite concerned when there is such an extreme variation in the results and claims of the benefit and harm of Vitamin E. Part of the differences may rest in different doses among different studies; some of the studies may be reporting amazing results in mice (which may or may not apply to humans), and some of the studies may have included only a very small numbers of test subjects, making the results less reliable. Be that as it may, a casual observer of the headlines for Vitamin E might find all the different headlines confusing, and an unscrupulous marketer might use some of the headlines to unfairly hype a product to maximize profits.

Vitamin C is another example. It is a vitamin that many people associate with the common cold. For many years it was assumed that taking a big dose of Vitamin C decreased susceptibility to a cold or helped fight off a cold after exposure. While one recent study supports this assertion5, other larger studies do not6. One recent study asserts that Vitamin C protects the lungs of smokers7. The headline of the article doesn't tell us that the experimental model for the study was guinea pigs and that the research may not exactly apply to humans. More worrisome is the study8 which suggests that postmenopausal women with diabetes who have a high intake of Vitamin C have an increased risk of death from cardiovascular disease. This is a large study published in a highly respected, peer-reviewed medical journal. Clearly the Vitamin C story becomes more complicated depending on who you are and what your co-existing diseases may be. Again, some of the headlines might lead a consumer to want to start taking large doses of Vitamin C and in some cases that may be a very poor decision.

One of the basic problems with vitamin science is that logical theory is often not proven out. The most common failed theory of vitamin science is that if a little is good, a lot must be better. This is actually rarely the case. Another logical theory often seen in vitamin science is that if it is true in mice, it must also be true in humans. While this may be the case sometimes, one should always be quite skeptical until appropriate confirmatory studies are done in humans. It is not a good idea to take vitamins based on research results seen only in mice.

In a surprising recent announcement9, cardiologists at the 2005 European Society of Cardiology Congress reported the unexpected finding that giving folate and Vitamin B6 to heart attack patients increased their risk for subsequent heart attack or stroke by 20%. Previous to the study most cardiologists agreed with the theory that Vitamin B6 and folate supplementation would have had the opposite effect because folate and Vitamin B6 had been shown to lower the level of homocysteine, a presumed indicator of cardiovascular risk. So while the theory that folate and Vitmin B6 should decrease cardiovascular risk was logically sound, in reality the opposite was found to be true.

So what is the conclusion to all of this? First, don't believe everything you read about vitamins, especially large doses of vitamins. More is not necessarily better. Second, discuss your "vitamin diet" with your physician. With all the "noise" in the headlines, I am afraid that there is a lot of information that is just not trustworthy. Third, just because someone has a grand vitamin theory or has a convincing web site or infomercial, don't assume the theory is true. Grand theories are often simply wrong. Finally, remember that the Internet doesn't necessarily distinguish between a trusted information source and someone who simply wants to sell something to you. The best vitamin plan starts with a discussion with your doctor.

Important Note: If you are pregnant, it is very important to follow the instructions of your doctor. Very good research has shown that taking appropriate vitamins during pregnancy is very good for you and your baby. The discussion above is directed toward adults who are not pregnant.

William Rice M.D.

References:

Vitamin E boost mice lifespan

Vitamin E Enhances Elders' Immune Systems

Study backs up claims over vitamin E and anti-aging

Vitamin E Linked to Higher Death Rates

High dose vitamin C reduced colds in Japanese study

Vitamin C for Preventing and Treating the Common Cold

Vitamin C to protect smokers' lungs

Vitamin C may increase mortality in diabetic women

Diet supplements can be harmful

© 2005 MyDNA.com