Almost half of the adult population in the United States takes nutritional supplements.  Most people are familiar with multivitamin pills.  However, both vitamin and mineral supplements now take the form of everything from pills to powders, gummies to bars, and widely popular drinks.  In addition, multivitamins are only one form of dietary supplement.  Products are widely available which single out an individual supplement such as Vitamin C, or paired supplements like Calcium plus Vitamin D.

People often take nutritional supplements for two main reasons:  to increase health if they are already healthy or to help slow or prevent an existing disease.  But is there any evidence that supplements are beneficial to either?  Many studies have been performed on whether vitamin and mineral supplements have any effect on disease.  There haven’t been any significant findings so the jury is still out on whether or not taking a multivitamin should be recommended for everyone.

Can a Nutritional Supplement Help Prevent or Cure a Disease?

If you take a supplement to prevent disease there is some important information you should know.  Since cardiovascular disease (which includes heart disease and stroke) and cancer are the leading causes of illness and death in The United States, The U.S. Preventative Services Task Force made a final recommendation on taking vitamin and mineral supplements for the primary prevention of cardiovascular disease and cancer.  They did not find that there was enough evidence that taking a multivitamin, single vitamin or mineral supplement, or paired vitamin and mineral supplements will help prevent cardiovascular disease (CVD) or cancer.

It’s what they did find that is more troubling.  “[T]he Task Force did find enough evidence to make a recommendation against using two specific vitamin supplements:  beta-carotene and vitamin E.  The Task Force found that:

  • Vitamin E supplements do not help or prevent CVD or cancer.
  • Beta-carotene supplements do not help or prevent CVD or cancer.  They also can increase the chance of getting lung cancer in people who are already at risk for lung cancer, such as current smokers.”

In addition, according to Harvard Health Publications, “a 2008 study in the Archives of Internal Medicine that tracked nearly 162,000 participants in the Women’s Health Initiative found that multivitamins have no effect whatsoever in 10 health-related categories including cancer, heart attack, and stroke.  Supplement takers didn’t live any longer either.”

Don’t Vitamin and Mineral Supplements Help Me Stay Healthy?

Supplement manufacturers would like you to believe that.  The vitamin and supplement industry is regulated by the FDA.  However, Harvard Health Publications notes that “in 1994, the Dietary Supplement Health and Education Act sharply restricted the FDA’s ability to regulate products marked as ‘dietary supplements,’ even though most people buy them for health and not nutrition.  Manufacturers can sell these products without submitting evidence of their purity, potency, safety, or efficacy.”

In addition, they state that “dietary supplements may legally contain vitamins, herbs, amino acids, enzymes, organ tissues, and a few other substances – in short practically any ingredient promoted as a way to bolster your diet, and presumably, your health.”  While there seem to be frequent news reports on the potential benefits of certain vitamins and minerals, “remember…that the good news from the latest study may eventually prove true, or it may be refuted by future studies.  Often, promising test-tube and animal studies don’t pan out in people. And certain types of human studies offer more definitive information than others.”

Can’t I Even Trust the Ingredient Labels?

The short answer is, no.  In 2009, the consumer watchdog organization ConsumerLab released a report and the findings were alarming.  They tested the quality and contents of 29 leading multivitamin and multi-mineral products for adults and children sold in The United States and Canada.  They found, “eight products did not meet claims stated on their labels or had other quality issues, while another 12 provided levels that may be too high for healthy people.  For example, one men’s multivitamin supplement contained over 2,000 mcg of folic acid, which is twice the safe upper limit for that vitamin.”

Big Money, Small Results

Harvard Men’s Health Watch states that in 2010, over $28 billion dollars was spent on vitamin and mineral supplements.  Prices for supplements can range from a few dollars to around $100 for more specialized or “designer” formulations.  If people have a desire for good health, they are more likely to adopt healthier habits, which often includes adding nutritional supplements to their diets in varying degrees.

However, when it comes to nutritional supplements, the evidence does not support the health benefit claims.  And even the claims must be followed by the disclaimer, “These statements have not been evaluated by the Food and Drug Administration.  This product is not intended to diagnose, treat, cure, or prevent any disease.”  So why do we keep buying them?

Dr. William Kormos, Editor in Chief of Harvard Men’s Health Watch and a primary care physician at Harvard-affiliated Massachusetts General Hospital says, “If people ask me if they should take a multivitamin, I usually ask, ‘Why do you think you need one?’  They say, well, I don’t eat this, I don’t eat that.  But a multivitamin is not going to replace the things missing from your diet.  Whatever money you are spending on your multivitamin, it’s probably better to spend it at the farmer’s market or the grocery store on healthy foods.”

Whether buying and preparing healthy foods is too confusing, too labor intensive, or just too much for most people to grasp, popping a pill, drinking a shake, or munching on a bar that is marketed to help improve our health seems like a quick and easy fix.  But buyer beware.  Is it really fixing anything?  Studies haven’t found clear evidence of that yet.


Supplements: a scorecard – Harvard Health. (2012, April).  Retrieved from

Fortmann, Stephen P., author. (2013).  Vitamin, mineral, and multivitamin supplements for the primary prevention of cardiovascular disease and cancer: A systematic evidence review for the U.S. Preventative Services Task Force.

Demystifying nutrition:  the value of food, vitamins, and supplements. (2013, March 5). Retrieved from: