People take vitamins to ensure optimum health in the face of a suspect diet or a less-than-ideal lifestyle.
Throughout my entire career, I have never heard of a multivitamin supplement causing harm or toxicity in adults. I have also never heard or seen a claim that these products could prevent another heart attack from happening in a person who recently suffered one. This is called secondary prevention, something nutritional supplements were never intended to accomplish.
A new study recently published in the journal Annals of Internal Medicine looked at the relationship between multivitamins/minerals and the avoidance of cardiovascular events in patients who recently experienced a heart attack. The trial looked at 1,708 patients who were at least 50 years of age or older and who had recently suffered a heart attack and they were randomized into two groups. The first group were given a high-potency multivitamin-mineral daily supplement and the other group received a placebo pill.
The two groups were followed for three years and the rates of heart attack, death, stroke, or cardiac surgery were tracked. The results reported no difference between either group in the rates of recurrent heart disease. Thus, the impression that the vitamins were useless was disseminated by these research findings.
“I have an active cardiology practice, and I tell my patients every session: ‘What are you doing? Why don’t you give the money to orphans, or if you don’t like people, the [Society for the Prevention of Cruelty to Animals] SPCA, because you’re not doing anything.’ At the end of it all, that’s the clinical message I give. From the scientific point of view, am I willing to close the door on vitamins? I think it’s still open maybe a few millimeters. . . . With these things you have to judge with your feet, and I’m not planning any vitamin studies,” said lead author of the study, Dr. G. Lamas.
Let’s take a closer look.
In this study, after three years of follow-up, almost 50% of the participants failed to finish the trial! In fact, only 47% of the study participants actually successfully completed the three year trial! As well, 27% of the patients were taking the vitamins compared with 30% in the placebo group. So, in actual terms, the group receiving the vitamins experienced an 11% risk reduction in cardiovascular events compared to the placebo group!
Unfortunately, Dr. Lamas failed to mention this rather important detail!
This is an excellent example of what I commonly refer to as experimenter bias and it is a very big problem in media or web-based stories that print stories based upon research findings which have been “cherry-picked” to suit the investigator’s own agenda.
Regarding the study results, Dr. Lamas offered this explanation, “It was not exactly clear to me that there would be no null effect, or no spillover effect, on some other system when used at these higher doses. And when you mix it, it’s hard to say if there would have been an ill effect or a beneficial effect. Probably the most important contribution of all of these vitamin studies is that we’re fairly certain that the majority of these vitamins are probably harmless even when given at very high doses. And that’s important.”
Of course, a multivitamin supplement should not be used for secondary prevention in very sick people. However, it is also quite unfair to harshly criticize the influence of vitamins on health in general because of this rather skewed research.
O’Riordan, M., “TACT: No CVD Benefit With High-Dose Multivitamins,” Medscape web site; http://www.medscape.com/viewarticle/817857, last accessed Dec. 17, 2013.
Lamas, G., et al., “Oral High-Dose Multivitamins and Minerals After Myocardial Infarction: A Randomized Trial,” Ann Intern Med 2013; 159(12): 797-805.