A new review doesn't add any value to supplements but at least it shows that people who spend money on supplements are more inclined to be developing a healthier lifestyle overall.

The review by  Council for Responsible Nutrition (CRN) consultant Annette Dickinson, Ph.D., and CRN's senior vice president, scientific and regulatory affairs, Duffy MacKay, N.D., only covered 20 articles, and those were all surveys anyway, so it's no surprise they found what they set out to find, that "overall, the evidence suggests that users of dietary supplements are seeking wellness and are consciously adopting a variety of lifestyle habits that they consider to contribute to healthy living." 

The review indicated that Americans who take dietary supplements are focused on wellness for the long term. MacKay observed, "Dietary supplement users typically make healthful habits part of each day, and many stick with their supplement regimen for years. Their supplement use doesn't appear to be something trendy, but more of a planned strategy they maintain for the long haul."  

So while multivitamins and plenty of other supplements don't do much good, at least companies can rest easy knowing people will continue to buy them for a long time.

But the authors say their review of surveys counters the concern that dietary supplement users are operating under a "halo effect" or may be seeking short cuts to good health.

They say the data indicate that dietary supplement users make better food choices in addition to taking supplements. They cite a report on the 2003-2006 National Health and Nutrition Examination Surveys (NHANES), which calculated nutrient intakes of dietary supplement users as compared to non-users and found that people who used dietary supplements had somewhat higher intakes of most nutrients from food alone (not counting the nutrients in dietary supplements) than people who were not supplement users.  

They also dispute that supplements are unnecessary for most. Using the the NHANES data again, they say that many Americans failed to consume the Estimated Average Requirement (EAR) for many nutrients when only naturally-occurring nutrients in foods were considered. Enrichment and fortification of foods decreased the prevalence of intakes below the EAR, and the use of dietary supplements further decreased shortfalls. For example, for vitamin A and calcium, more than half of NHANES respondents fell short. Food fortification lowered the prevalence of shortfalls to 50 percent for these nutrients. Supplementation drove the prevalence of shortfalls down even further, but 33 percent of the respondents still fell short.  

"It's important to give dietary supplement users credit for their efforts to improve their overall wellness profile with thoughtful choices," said Dr. MacKay, "The scientific evidence indicates that they tend to incorporate these products into their lifestyles as part of a broader focus on healthy living, with supplement use just one of a constellation of smart, healthy habits."

That's certainly true. Some people buy magic soap and organic food too, that is the miracle of capitalism. And supplements are unlikely to harm people, but while it is good that supplement users display other healthy behaviors, supplements are not a causal link. People take supplements because they want to be healthier, the supplements did not make them healthier.

Paper: "Health Habits and Other Characteristics of Supplement Users" - Nutrition Journal, 2014, 13:14