Many people ask me if they need to take a multivitamin every day, or report to me guiltily that they don’t remember to take their vitamins. In the aisles of drug stores, I see signs saying “doctors recommend daily use of a multivitamin." Vitamin and supplement use in the U.S. is BIG business. Annual sales of supplements were reported to be $34.8 billion in 2013 (The State of Supplement Sales in 2014). My experience is that many people believe that it's clear that taking a vitamin is the right thing to do. I would posit it warrants a bit more thought.
In the 1920’s the United States started adding iodine to table salt to prevent the development of goiter, followed by adding Vitamin D to milk to prevent rickets. Both of these were fantastic public health interventions which helped curb disease. In the 1940’s the first multivitamin tablet was produced. Although clinical deficiencies of vitamins, except iron, are rare now in the U.S., the industry has continued to grow, partly based on marketing claims that multivitamins can prevent illness and death.
In December 2013 a group of doctors published an editorial titled "Enough is enough: stop wasting money on vitamin and mineral supplements". This editorial was based on a high quality study they conducted of a large amount of data on vitamins and supplements. They used the second highest quality of science we have for searching for true effect, called a systematic review. Their conclusions were that there is “no clear evidence of a beneficial effect of supplements on all-cause mortality [death by any cause], cardiovascular disease, or cancer.” This study provided the evidence to develop the current USPSTF recommendations on the use of multivitamins for the prevention of cancer and cardiovascular disease.
Mark Twain once said, "Facts are stubborn things, statistics are more pliable."
In this recent article NPR reports a positive slant to taking a multivitamin every day. Stating that in general, Americans are not meeting their nutritional needs and that taking a multivitamin might fill that gap and citing the Physicians Health Study II. The Physician Health Study II showed a very small decrease in cancer amongst men who took multivitamins over 12 years. The reason this positive study didn’t sway the results of the systematic review mentioned above is because it was a relatively small study with a relatively small benefit and in the context of the larger body of evidence it wasn’t significant enough to make a difference. The other article cited in the NPR article claimed that multivitamins can reduce heart disease in women. However, this study was also not as high quality as the systematic review. Conclusions in this article about true effect are on shaky ground.
There is also growing concern about the risks of excess intake of vitamins and minerals. Increasingly popular fortified foods and beverages, like Vitamin Water, have added more vitamins and minerals to our diet. This study performed in 2012, which looked at a sample of adults, showed that although taking vitamins did help people reach Estimated Average Requirements of many vitamins, it also led to intake levels above the Tolerable Upper Level Intake for many other vitamins.
Based on my understanding of the benefits and risks of supplementing with certain individual vitamins and minerals (more to come on Vitamins E, A, D and selenium), I believe that a daily multivitamin is not needed for a healthy person who has access to whole foods. There are some individual scenarios when supplementing with specific vitamins or minerals is of value to health (see “Special Considerations for Certain Population Groups”), but this doesn’t apply to the general population.
The balance of nutrients and vitamins in whole foods has evolved and is much more complex than can be re-created in a pill. According to the federal government's 2010 Dietary Guidelines for Americans, "nutrients should come primarily from foods. Foods in nutrient-dense, mostly intact forms contain not only the essential vitamins and minerals that are often contained in nutrient supplements, but also dietary fiber and other naturally occurring substances that may have positive health effects."
So, I wouldn't feel quite so guilty about missing that multivitamin. Perhaps it's best to focus your energy on finding new enchanting fruits and vegetables.