Study backs multivitamins' ability to prevent nutrient shortfalls with hard data

13-Aug-2017 - Last updated on 16-Aug-2017 at 06:35 GMT

A study published last week in the journal Nutrients adds another brick in the wall backing the ability of multivitamins to fill in nutrient shortfalls. While this notion is taken for granted among experts in the dietary supplement field, it is still sometimes discredited by health influencers and in the mainstream press.

The study, by a group of authors led by Jeffrey Blumberg, PhD, of Tufts University in Medford, MA combed through data from the NHANES (National Health and Nutrition Examination Surveys) gathered in the 2009-2012 time frame. The authors found that the frequent use of multivitamin and mineral supplements (MVMS) achieved exactly what the manufacturers of these products claim they will do, namely prevent the shortfall of important nutrients.

Decreasing micronutrient inadequacies

“Except for calcium, magnesium, and vitamin D, most frequent MVMS use (≥21 days/30 days) virtually eliminated inadequacies of the nutrients examined, and was associated with significantly lower odds ratios of deficiency for the examined nutrient biomarkers except for iron. In conclusion, among US adults, MVMS use is associated with decreased micronutrient inadequacies, intakes slightly exceeding the UL for a few nutrients, and a lower risk of nutrient deficiencies,” the authors wrote.

“By this point, you would almost feel as if you don’t need to do this kind of research,” Duffy MacKay, ND, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition told NutraIngredients-USA. “But we know this is a very impressive group of authors with a lot of experience in vitamins, minerals and individual nutrients. It is important to have this kind of confirmation of the idea that use of multivitamins is effective in increasing micronutrient intake.”

The authors did an exhaustive statistical analysis of the data that included survey results from 10,698 adults, even split between men and women. A survey on supplement use was included as part of the NHANES household interview that determined frequency of use and also helped the authors hone in MVMS themselves (defined as containing 9 or more of the nutrients of interest), and eliminate single nutrient and other types of supplements. About 28% of respondents reported taking a MVMS, and among this group compliance was high, with 20% of overall respondents saying they had taken one of these products more than 21 days out of the preceding 30 days.

Multivitamins take up where fortification leaves off

Lead author Jeffrey Blumberg PhD, who is the lead scientist of the Antioxidants Research Laboratory at Tufts, said the data help support the idea that the use of MVMS can be in important support for overall health. It is often claimed that diet alone should be sufficient to supply all of the nutrients that are critical in maintaining health. Widespread micronutrient fortification in food has in fact helped eliminate certain deficiency diseases like rickets and beriberi. But Americans still consistently come up short in the kind of full-spectrum micronutrient intake that could support optimum health, he said.

“Food fortification — particularly vitamin D in milk and vitamin A in reduced fat milk; iodine in salt; B vitamins, now including folic acid, and iron in refined flour — has been one of the huge public health wins in the US this past century. In spite of this past success, due partly to changes in our current dietary pattern, there are now 11 “underconsumed” or shortfall micronutrients — vitamins A, C, D, E, K, folate and choline and the essential minerals calcium, iron, magnesium, and potassium — recognized in the Dietary Guidelines for Americans 2015-2020. Multivitamin/multi-mineral supplements can help fill many, but not all, of these gaps as illustrated in our recent study of the latest NHANES dataset from 2009-2012,” Blumberg said.

Consistency gives best results

Blumberg said his group found that those users who were most consistent in their MVMS use derived the most benefit. This is no surprise, but it’s an important data point in light of the fact that another study using NHANES data by Kantor et al. that was released last year found that the use of these supplements has been declining.

“Perhaps not surprisingly, we found MVMS use was associated with a lower prevalence of inadequacy (i.e., intakes lower than the Estimated Average Requirement or EAR) for 15 of the 17 micronutrients we examined and contributed significantly to the nutritional well-being of the users. Interestingly, we report for the first time that those users who best complied by taking their multivits for 21 or more days per month eliminated inadequacies of intake for all the nutrients except for calcium, magnesium, and vitamin D and lowered the odds ratios of deficiency for most all the blood biomarkers included in NHANES,” Blumberg said.

Old habits die hard

With the results from this study, which confirm other similar studies, why then does the notion persist that multivitamins are merely a frivolous habit created by marketing? The way health professionals such as dietitians, pharmacists and physicians are trained could complicate the question. Many experts in the dietary supplement field have observed that the contribution that supplements can make to overall nutrient status forms at best an afterthought in most curricula in these professions.

“Regrettably, there appears to be a great tenacity to old ways of thinking, e.g., you can get all the nutrition you need if you just eat a healthy, balanced diet — and then ignoring how most people actually eat and what they actually require. . . . Also, as our understanding about higher nutrient requirements for optimal health and wellness grows, particularly among older adults, it is clear that it can be quite difficult to achieve these intakes of selected nutrients from commonly available food choices,” Blumberg said.

MacKay said with the conclusion of this paper is hardly ground-breaking, having hard data to support that conclusion is vital in negotiations with health officials who hold the public purse strings. A recent bill has been introduced by Rep. Dave Brat, R-VA that would allow WIC benefits to be used to pay for multivitamins. “This is probably a good idea,” is not as effective a reason to support such a change as “we can prove this is a good idea,” MacKay said.

“When you take the data as it is compiled in this paper it becomes a much more compelling argument,” MacKay said.

Source: Nutrients
“Impact of Frequency of Multi-Vitamin/Multi-Mineral Supplement Intake on Nutritional Adequacy and Nutrient Deficiencies in U.S. Adults”

Nutrients 2017, 9(8), 849; doi:10.3390/nu9080849

Authors: Blumberg JB, Frei BB, Fulgoni VL, Weaver CM, Zeisel SH