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TalkingNutrition

Providing perspectives on recent research into vitamins and nutritionals

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Multivitamins aren’t Drugs but they are Supplements

By Michael McBurney

Headlines might have you believe vitamin supplements are a wasted investment. How can efforts to achieve recommended nutrient intakes be so distorted? The Dietary Reference Intakes (DRIs) are nutrient reference values set the by Institute of Medicine of The National Academies. They are intended to serve as a guide for good nutrition.

The reality is many, many people are not consuming enough vitamin and mineral -rich foods to meet the DRIs.

The second fact is people using multivitamin supplements are more likely to meet the DRI.

The third misfortune is that most dietary supplement interventions have been conducted without consideration of nutrient status. Time and time again, volunteers for RCTs do not reflect the general public in terms of diet, physical activity or health.  

The fourth fact: Because of the millions of dollars spent recruiting and executing these RCTs and researchers are recognized for publishing scientific articles, cohorts tend to be leveraged long after the RCT is terminated.  Such an approach may make sense for a group who were exposed to a chemical, i.e. hormone replacement therapy or who smoked and quit. It makes little sense for nutrition where everyone continues to eat and have some level of nutrient status.

Fifth, researchers choose to study other nutrient-disease interactions that were not part of the original RCT design. In other words, researchers use (abuse?) the data to examine hypothetical relationships. Unintended, unplanned relationships. As an example, the Selenium and Vitamin E Cancer Prevention Trial (SELECT) recruited men with prostate cancer. Vitamin E and selenium were administered as treatments for 7-12 years. Cancer incidence was the primary outcome. Researchers are retrospectively assessing another outcome, e.g. cataracts, in a cancer-prone population. Again, without any assessment of nutrient status. The inference is that vitamin E supplementation isn’t beneficial even though  a meta-analysis of prostate cancer intervention trials found each 5.8 µmol/L increase in blood α-tocopherol concentrations was associated with a 21% decrease in prostate cancer risk.

Nutrients are not drugs. Nutrients don’t prevent or mitigate disease. Nutrients are essential for life. DRIs have been established for nutrients. Most people do not consume the DRIs recommended for their age and sex. Using a multivitamin supplement can help them safely meet recommended intakes. What more is there to be said?

Main Citation

Christen WG, Glynn RJ, Gaziano JM, Darke AK, Crowley JJ, Goodman PJ, Lippman SM, Lad TE, Bearden JD, Goodman GE, Minasian LM, Thompson Jr IM, Blanke CD, Klein EA. Age-related cataract in men in the selenium and vitamin E cancer prevention trial eye endpoints study: A randomized clinical trial. 2014 JAMA Opthalmol doi: 10.1001/jamaopthalmol.2014.3478

Other Citations

Cui R, Liu Z-Q, Xu Q. Blood α-tocopherol, γ-tocopherol levels and risk of prostate cancer: A meta-analysis of prospective studies. 2014 PloS ONE doi: 10.1371/journal.pone.0093044

Weaver CM, Dwyer J, Fulgoni VL, King JC, Leveille GA, MacDonald RS, Ordovas J, Schnakenberg D. Processed foods: contributions to nutrition. 2014 Am J Clin Nutr doi: 10.3945/ajcn.114.089284

Wallace TC, McBurney M, Fulgoni VL. Micronutrient intakes in the United States, 2007-2010. J Am Coll Nutr doi: 10.1080/07315724.2013.846806


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