This article published in the Archives of Internal Medicine in October 2011 has certainly created media frenzy.  The Wall Street journal reads “A succession of large-scale human studies, including two published earlier this month in leading medical journals, suggests that multivitamins and many other dietary supplements often don’t have health benefits—and in some cases may even cause harm.”

Well, well, well. Shall we look closely at this latest paper? I would encourage you to read it so I do not bore you with all the details. In brief, this study was an observational study designed to look for or “observe” correlations, not causation. A large group of mostly Caucasian women (age 55 to 69 years old) were asked to fill questionnaires including food frequency and supplement use in 1986, 1997 and 2004 (18 years span). Supplements included multivitamins, vitamin A, beta-carotene, B6, folic acid, B complex, C, D, E and minerals iron, calcium, copper, magnesium, selenium and zinc. Upon review, a few key points jumped at me. After all, it is Halloween today!

First of all, linking supplements use and death rate is quite far-fetched. One does not take supplements to ward off death (we will all end there eventually) but to help maintain basic physiological functions with the hope of a better quality of life, not necessarily an extension of your life.

Second, no dosage, source of the ingredients or frequency of use were indicated. Can you treat the data of a subject taking 1000 times the recommend level for a vitamin in the same way as a subject who consumed only 20% of  the recommended level? I would not. The study lasted 18 years with 3 time points. This brings the question: Did the subjects take supplements continuously during those years? I highly doubt it.

Thirdly, after reading the very sophisticated statistical analysis, it dawned on me that hormone replacement was not taken into consideration. As you may recall, the Women’s Health Initiative study where subjects took hormone replacement therapy was stopped because the group who took the hormones had a significant increased risks of heart attack, stroke, breast cancer and death.  It is possible that the beneficial effects of supplements are buried under the harmful effects of hormone, no pun intended.

I could go on and on but I think you got the just of it. Wisely the study’s authors pointed out some of the limitations of the study and I quote “we did not have data regarding nutritional status or detailed information of supplements used”.  That is a huge deal in my opinion. They also indicated that there may be some residual confounding factors such as occurrence of cardiovascular diseases, cancer or other diseases during those years that were not taken into consideration in the data analysis.  And finally in their conclusions, contradictory statements are made. One statement reads: ”based on existing evidence, we see little justifications for the general and widespread use of dietary supplements. We recommend that they be used with strong medically based cause such as symptomatic nutrient deficiency disease.” And the next sentence reads “we found that most dietary supplements were unrelated to total mortality rate”.

So with that said, I hope that you won’t let the media scare you. However I need to say that there is no substitute for a healthy diet. However for us, women, it is hard to get all the recommended nutrients with the amount of calories we eat. Make informed choices and don’t let the media frenzy frightens you or dictates your decision. Continue taking your supplements judiciously if you feel they make a difference for you. It’s your health!

(Mursu, J., K. Robien, et al. (2011). “Dietary Supplements and Mortality Rate in Older Women: The Iowa Women’s Health Study.” Archives of internal medicine 171(18): 1625-1633.)