Nutrient supplementation and cognitive function: A pilot study

This study was conceived within the context of the current IQ/Nutrient debate which cites research from both England and America and commenced with the study of Benton & Roberts ( 1988). As a contribution to this debate, the current research was undertaken as a pilot study to further investigate the nature of the relationship between nutrient supplementation and cognitive function. Young schoolchildren aged 5-10 years were selected on the basis of a verbal cognitive deficit relative to nonverbal cognitive competence and supplemented for a 11 week period. Fiftyseven schoolchildren with verbal/nonverbal IQ deficits of at least 10 points were randomly assigned to one of the three treatment groups and participated in a double-blind study to evaluate treatment effects. Two active nutrient treatments were evaluated for differential effect against a placebo treatment. General versus specific forms of nutrient supplementation differentiated the active nutrient treatments. The general form of supplementation was a broad based mineral/vitamin supplement based on the 100% RDA level. The specific form of supplementation was individualised and based on identified states of nutrient deficiency. Direction of improvement in cognitive function was assessed pre and post intervention using both psychometric and significant other (parent and teacher) questionnaire measures. Treatment effect on verbal versus nonverbal functioning was of interest so measures were selected as discriminators of either verbal or nonverbal cognitive function. After supplementation, those children who received the specific form of nutrient supplementation did better on verbal and nonverbal measures than both the general form of supplementation and the placebo treatment. The only significant treatment effect was found on a nonverbal psychometric measure of concentration and short term visual memory. This effect was found for both the specific and placebo treatments. No significant effects were found for the general form of supplementation. In the light of these findings, the theoretical and practical implications of the current study are discussed