Despite its well-known health benefits, a daily multivitamin may not help students ace exams or even make it to school on time, suggests a new study of New Jersey elementary school kids.

The finding counters previous research that reported improved academic performance and behavior with supplements use, particularly for underserved children at risk of a poor diet.

“We wanted to design a study that would have readily translated into the real world, so that if the results were positive you could lobby for school-based programs,” lead researcher Dr. Adam Perlman of the University of Medicine and Dentistry of New Jersey told Reuters Health. “Unfortunately, our research didn’t show that.”

Perlman and his colleagues followed nearly 700 inner city third- through sixth-grade students over the course of the 2004-2005 school year. Half of the kids received a chewable multivitamin supplement every school day during lunch or a snack period, while the other participants took a placebo pill that was similar in appearance and taste, but without active ingredients.

At the end of the school year, the researchers uncovered no differences in standardized test scores, grade point averages, late arrivals or absenteeism between the two groups of kids.

As the team reports in the Journal of the American Dietetic Association, the supplement used in the study provided only 12.5 percent and 50 percent of the daily values of calcium and iron, respectively, along with 100 percent of most other vitamins and minerals.

Given that a number of the participants were found to have inadequate levels of these two nutrients prior to the start of the supplementation program, some of the potential effects may have been limited from the start.

“It would have been nice if a simple multivitamin alone was enough,” noted Perlman. “But clearly that’s not the answer. Maybe you need a higher potency multivitamin or a more comprehensive lifestyle program - one that not only includes nutrition, but also exercise and other factors that could impact school performance and behavior.”

Dr. Howard Taras of the University of California, San Diego, thinks the “case is closed” on any direct effect of vitamin supplements on academic achievement - at least in developed countries.

“Only in areas of the world where there is malnutrition with severe micronutrient deficiencies can we expect supplements to improve how children function mentally,” Taras, who was not involved in the current study but has also investigated the link, told Reuters Health by email.

He added that the supplement industry funded much of the research that had previously shown beneficial effects in countries such as the U.S. and United Kingdom. The current study was funded by a non-profit, Nourish America-Vitamin Relief USA, through the U.S. Department of Education. The Tishcon Corporation, which sells supplements, provided the multivitamins and inactive placebo pills, and Colgate provided toothbrushes.

Both Perlman and Taras emphasized that the findings don’t suggest that children shouldn’t take multivitamins.

“Although this study didn’t show multivitamins to be the answer, we need to continue to focus on strategies to improve the health and wellbeing of children,” said Perlman, “not only to help them maintain their physical and emotional health, but also perhaps to help them do better in school.”

SOURCE: Journal of the American Dietetic Association, July 2010.