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The Effect of Vitamin-Mineral Supplementation on the Intelligence of American Schoolchildren: A Randomized, Double-Blind Placebo-Controlled Trial

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Many medical, nutrition, and education professionals have long suspected that poor diet impairs the academic performance of Western schoolchildren; academic performance often improves after improved diet. However, others have suggested that such academic gains may be due to psychologic effects rather than nutrition. To resolve this issue, two independent research teams conducted randomized trials in which children were given placebos or low-dose vitamin-mineral tablets designed to raise nutrient intake to the equivalent of a well-balanced diet. Both teams reported significantly greater gains in nonverbal intelligence among the supplemented groups. The findings were important because of the apparent inadequacy of diet they revealed and the magnitude of the potential for increased intelligence. However, none of the ten subsequent replications, or the two original trials, were without limitations leaving this issue in controversy. To determine if schoolchildren who consume low-dose vitamin-mineral tablets will have a significantly larger increase in nonverbal intelligence than children who consume placebos in a study that overcomes the primary criticisms directed at the previous 12 controlled trials. A double-blind, placebo-controlled trial using stratified randomization within each teacher's class based on preintervention nonverbal intelligence. Two "working class," primarily Hispanic, elementary schools in Phoenix, Arizona, participated in the study. Slightly more than half the teachers in each school distributed the tablets daily to 245 schoolchildren aged 6 to 12 years. Daily vitamin-mineral supplementation at 50% of the U.S. daily recommended allowance (RDA) for 3 months versus placebo. Post-test nonverbal IQ, as measured by the Wechsler Intelligence Scale for Children-Revised (WISC-R), while controlling for pretest nonverbal IQ as a covariate. FOUR MAIN RESULTS: First, a significant difference of 2.5 IQ points (95% CI: 1.85-3.15) was found between 125 children given active tablets and 120 children given placebo tablets (p = 0.038). Second, this finding is consistent with the mean 3.2 IQ point net gain found in the 12 similar but less rigorous studies. Third, a significantly higher proportion of children in the active group gained 15 or more IQ points when compared to the placebo group (p < 0.01). Fourth, although 81 matched pairs produced no difference at all in nonverbal IQ gain, the modest 2.5 IQ point net gain for the entire sample can be explained by the remaining 24 children who took active tablets, and had a 16 point higher net gain in IQ than the remaining 19 placebo controls. This study confirms that vitamin-mineral supplementation modestly raised the nonverbal intelligence of some groups of Western schoolchildren by 2 to 3 points but not that of most Western schoolchildren, presumably because the majority were already adequately nourished. This study also confirms that vitamin-mineral supplementation markedly raises the non-verbal intelligence of a minority of Western schoolchildren, presumably because they were too poorly nourished before supplementation for optimal brain function. Because nonverbal intelligence is closely associated with academic performance, it follows that schools with children who consume substandard diets should find it difficult to produce academic performance equal to those schools with children who consume diets that come closer to providing the nutrients suggested in the U.S. RDA. The parents of schoolchildren whose academic performance is substandard would be well advised to seek a nutritionally oriented physician for assessment of their children's nutritional status as a possible etiology.
... These are essential throughout the life but the period of childhood and adolescence is more important, as it is marked by rapid growth and development. Review of literature suggests that deficiency of minerals (calcium, iron, selenium and zinc) and Vitamins (Vitamin A, 25 Hydroxy Vitamin D, Vitamin B12 and Folate) during childhood and adolescence have negative impact on general health, growth, neuropsychological behavior, cognitive and motor development, intelligence quotient, attention, learning, memory, language ability and educational achievement [1][2][3][4][5][6][7][8][9]. Iron, folate or vitamin B12 deficiency results in anaemia which has a negative impact on work capacity, intellectual performance, and child cognitive development [1]. ...
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Introduction Childhood and adolescence require adequate amount of micronutrients for normal growth and development. The primary objective of study was to assess the prevalence of deficiencies of Vitamins (Vitamin A, 25 Hydroxy Vitamin D, Vitamin B12 and Folate) and minerals (Calcium, Zinc, Selenium and Iron), among urban school going children aged 6–11 and 12–16 years in ten cities of India. Secondary objective was to find the association between micronutrient deficiencies with sociodemographic and anthropometric indicators. Methods A multi-center cross-sectional study was conducted across India. Participants in the age groups of 6 to 11 years (group 1) and 12 to 16 years (group 2) were selected from randomly chosen schools from each center. Data on socio economic status, anthropometric measures was collected. Blood samples were collected for biochemical analysis of micronutrients. Point estimates and 95% confidence intervals was used to assess the prevalence of deficiencies. Associations were observed using chi square, student t test and ANOVA test. Results From April 2019 to February 2020, 2428 participants (1235 in group 1 and 1193 group 2) were recruited from 60 schools across ten cites. The prevalence of calcium and iron deficiency was 59.9% and 49.4% respectively. 25 Hydroxy Vitamin D deficiency was seen in 39.7% and vitamin B12 in 33.4% of subjects. Folate, Selenium and Zinc were deficient in 22.2%, 10.4% and 6.8% of subjects respectively. Vitamin A deficiency least (1.6%). Anemia was prevalent in 17.6% subjects and was more common among females. Conclusion One or more micronutrient deficiencies are found in almost one half of school going children in urban area. Hence efforts must be made to combat these on priority. Trial registration number CTRI/2019/02/017783 .
... 3 Nutrition anaemia is caused by deficiency of iron, folate and vitamin B12. 4 The association between nutritional status and health, cognition and educational achievement is established among the school going children. 5 Deficiency of micronutrients and nutrients delays cognitive and motor development and is associated with low intelligence quotient (IQ). [6][7][8] There is a consensus on the fact that iron deficiency has a negative impact on cognition, behaviour and motor skills. It has been found that haemoglobin though correlates to cognitive performance, iron supplementation improves cognitive functions regardless of the haemoglobin levels. ...
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Introduction Childhood and adolescence are the period of rapid physical and cognitive growth and development, requiring adequate nutrition. Malnutrition in the form of undernutrition or micronutrient deficiency or overweight/obesity affects the health, cognition and educational achievement of this age group. The objective of this study is to assess the prevalence of calcium, iron, zinc, selenium, folate, vitamin A, 25 hydroxy vitamin D and vitamin B12 deficiencies in the serum and haemoglobin, ferritin and lead levels and its association with reported dietary intake and cognitive abilities, in urban school going children aged 6–16 years in 10 cities of India. Methods and analysis A multicentric cross-sectional study will be conducted to recruit 2400 participants (240 per site) across India. Participants will be selected using random sampling and will be categorised into age groups of 6–11 years and 12–16 years, with equal distribution. Data on socioeconomic status, anthropometric measures and 3-day dietary intake and cognitive performance will be collected. Blood samples will be collected for biochemical analysis of micronutrients. Findings will estimate the prevalence of micronutrient deficiencies and their association with dietary habits and cognitive functioning. Ethics and dissemination Study protocol has been reviewed and approved by institutional ethics committee of all 10 participating sites. Results will be shared and published in a peer-reviewed journal, so that the findings will be helpful for the stakeholders in planning nutritional interventions for targeted groups. Trial registration number CTRI/2019/02/017783.
... They should eat at least 300 g fresh fruit and 300 g fresh vegetables daily. Positive effects of micronutrient supplements on non-verbal intelligence in adolescents with an unhealthy diet (< 50% der RDA) (p < 0.02) Table 2. Effects of multivitamin preparations on cognitive function in children and adolescents -a selection [20][21][22][23][24][25]. ...
... Therefore, improving micronutrient status to combat the adverse health consequences of deficiencies in Vietnamese children has the potential to benefit those affected by both under-or over-nutrition. The practice of single or multiple micronutrient supplementation in school children has been widespread in high-income 14,15 , as well as low-and middle-income countries including Vietnam [16][17][18][19] , and reported to reduce the prevalence of vitamin A 20 , zinc 17 and iron deficiencies 19 , as well as anaemia 16,17,19 . However, few of these studies, and none in Vietnam, have examined their efficacy in relation to child anthropometric status 21 . ...
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We aimed to determine the efficacy of multiple micronutrient supplementation on the biomarkers of iron, zinc, and vitamin A status across anthropometric status categories in Vietnamese school children. In this 22-week randomised controlled trial, 347 undernourished, normal weight, or overweight/obese children aged 6–9 years were allocated to receive every school day a multiple micronutrient supplement (10 mg iron, 10 mg zinc, 400 µg vitamin A) or a placebo. Haematological indices; circulating ferritin, zinc, and retinol (corrected for inflammation); and C-reactive protein were measured at baseline and 22 weeks. At week 22, linear mixed models showed that mean corpuscular volume increased by 0.3 fL, serum ferritin by 9.1 µg/L, plasma zinc by 0.9 µmol/L, and plasma retinol by 15%, and the prevalence of zinc deficiency decreased by 17.3% points in the intervention group compared to placebo. No intervention effects were found for other haematological indices, or the prevalence of anaemia. Multiple micronutrient supplementation for 22 weeks improved the biomarkers of zinc and vitamin A status and some biomarkers of iron status, and reduced the prevalence of zinc deficiency in Vietnamese school children. Trial registration: This trial was registered on 06/09/2016 at www.anzctr.org.au as ACTRN12616001245482.
... In spite of the brain is elaborated from substances present in the diet (sometimes exclusively, for vitamins, minerals, essential amino-acids and essential fatty acids). Also, Schoenthaler et al.,(2000), found that vitamin-mineral supplementation markedly increased the non-verbal intelligence of a minority of Western schoolchildren, presumably because they were too poorly nourished before supplementation for optimal brain function. So, nonverbal intelligence is closely associated with academic performance. ...
... Furthermore, there is evidence of an inverse relationship between 25-hydroxyvitamin D measured in neonatal dried blood samples and risk of both autistic spectrum disorder 17,18 and schizophrenia 19 . Intervention studies conducted in early childhood have shown that administration of multivitamins containing vitamin D can reduce symptoms in children with autistic spectrum disorder 20 , and improve normal childhood cognition 21 . To date, no studies have investigated whether vitamin D supplements can reduce seasonal patterning in autism or other causes of learning disability. ...
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Learning disability varies by month of conception. The underlying mechanism is unknown but vitamin D, necessary for normal brain development, is commonly deficient over winter in high latitude countries due to insufficient ultraviolet radiation. We linked the 2007–2016 Scottish School Pupil Censuses to Scottish maternity records and to sunshine hours and antenatal ultraviolet A/B radiation exposure derived from weather stations and satellites respectively. Logistic regression analyses were used to explore the associations between solar radiation, then ultraviolet B, and learning disabilities, adjusting for the potential confounding effects of month of conception and sex. Of the 422,512 eligible, singleton schoolchildren born at term in Scotland, 79,616 (18.8%) had a learning disability. Total antenatal sunshine hours (highest quintile; adjusted OR 0.89; 95% CI: 0.86, 0.93; p < 0.001) and ultraviolet B exposure (highest quintile; adjusted OR 0.55; 95% CI: 0.51, 0.60; p < 0.001) were inversely associated with learning disabilities with evidence of a dose-relationship. The latter association was independent of ultraviolet A exposure. Significant associations were demonstrated for exposure in all three trimesters. Low maternal exposure to ultraviolet B radiation may play a role in the seasonal patterning of learning disabilities. Further studies are required to corroborate findings and determine the effectiveness of supplements.
... Acute multivitamin supplementation has also been shown to improve contentment and cognitive task performance in adults [8]. In children, multivitamin supplementation for 12 weeks has been shown to increase intelligence [19] and cognitive performance, but not mood [6], whereas 4-month supplementation has been shown to have no effect on cognition [20]. These findings together demonstrate that multivitamin supplementation, particularly those higher in B vitamins, may improve cognition and mood, which might be facilitated by improving brain health, although more targeted investigations into the relationship between B vitamins and neuromarkers of health are required. ...
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A diet rich in B-group vitamins is essential for optimal body and brain function, and insufficient amounts of such vitamins have been associated with higher levels of neural inflammation and oxidative stress, as marked by increased blood plasma homocysteine. Neural biomarkers of oxidative stress quantified through proton magnetic spectroscopy (1H-MRS) are not well understood, and the relationship between such neural and blood biomarkers is seldom studied. The current study addresses this gap by investigating the direct effect of 6-month high-dose B-group vitamin supplementation on neural and blood biomarkers of metabolism. Using a randomized, double-blind, placebo-controlled design, 32 healthy adults (20 female, 12 male) aged 30–65 years underwent blood tests (vitamin B6, vitamin B12, folate, and homocysteine levels) and 1H-MRS of the posterior cingulate cortex (PCC) and dorsolateral prefrontal cortex (DLPFC) before and after supplementation. Results confirmed the supplement was effective in increasing vitamin B6 and vitamin B12 levels and reducing homocysteine, whereas there was no change in folate levels. There were significant relationships between vitamin B6 and N-acetylaspartate (NAA), choline, and creatine, as well as between vitamin B12 and creatine (ps < 0.05), whereas NAA in the PCC increased, albeit not significantly (p > 0.05). Together these data provide preliminary evidence for the efficacy of high-dose B-group supplementation in reducing oxidative stress and inflammation through increasing oxidative metabolism. It may also promote myelination, cellular metabolism, and energy storage.
... However, the factors like digestion capacity, absorption, metabolic system, and demand have a significant impact on nutritional status along with the food intake. It has been focus on the interrelationship between the possible causes and effects such as metabolic imbalances and developmental abnormalities closely related with attention deficit disorder(Breakey 1997; Garipardic et al. 2017), learning disorders and intellectual development violence and other serious antisocial behavior, probably related to the cell danger response (Carlton et al. 2000;Schoenthaler et al. 2000;Naviaux 2014). Mitochondrial dysfunction, inflammation, immune dysregulation, and oxidative found in the brain of ASD individuals indicate the biological basis for the reported behavioral problems ( Goh et al. 2014;Rossignol and Frye 2014;Naviaux et al. 2015). ...
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Vitamin or mineral supplementation is considered to be the most commonly used medical treatment for autism spectrum disorder (ASD), in addition to other interventions such as neurological and psychological interventions. There is not much evidence of therapeutic efficacy between vitamin and mineral supplementation and improvements in ASD. However, several researchers have noted that patients with ASD have various metabolic and nutritional abnormalities including issues with sulfation, methylation, glutathione redox imbalances, oxidative stress, and mitochondrial dysfunction. There is some evidence that vitamin and mineral supplementation may support these basic physiologic processes. Recently, the nutritional status of ASD patients has been gaining focus in this particular area. Pointing out the nutritional status as a potential etiological factor for attention/communication disorders, more importance has been given to this particular point. Moreover, autistic specific considerations like the feature and behavior of ASD might be increased or at least fall in the higher risk due to the sub-optimal nutritional status.
... A placebo controlled three-month study of 20 autistic children found multivitamins with even low doses of vitamin D (150 units or 3.75 mcg) significantly improved sleep and gastrointestinal problems [46]. Further evidence that vitamin D may favorably affect mentation comes from a series of randomized controlled interventional studies evaluating the effect of vitamin D containing multivitamins on normal childhood cognition (for a review, see Schoenthaler et al. [47]). All 14 studies they reference, including their own, reported small (1-2%) to modest (5-6%) improvements, most of them significant, usually in nonverbal IQ; the first study was reported in the Lancet in 1988 [48] ( Fig. 3). ...
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Thesis
p>This study had two components. The first was a population survey to ascertain the prevalence of behaviour problems and/or allergy and their associated risk factors. The second part of the study was a randomised placebo controlled cross-over-trial. The study population consisted of 2731 3-year-olds resident on the Isle of Wight. There was a 70% response rate to the behavioural assessment which consisted of 3 parent completed, validated questionnaires. 50% of the population were also assessed for atopic status (at least one positive skin prick test of ≥ 2mm mean wheal diameter) and allergic symptoms (questions from the International Study Asthma Allergies in Childhood). There was no difference between those who consented to assessment and those who did not. 277 of these children (10%) completed a 4 week randomised placebo controlled cross-over trail. Children defined as both atopic and hyperactive were selected and matched for sibship position, maternal education and month of birth with 3 other children, who were atopic only, hyperactive only or neither. The challenge was 20 mg of artificial food colourings (sunset yellow, tartrazine, carmoisine, and ponceau 4R) and 45mg of sodium benzoate, within a daily mixed fruit juice vehicle. The challenge and placebo were shown to be indistinguishable in taste and appearance. The child’s attention, impulsivity and activity was assessed with weekly clinic-based tests, and a daily parental questionnaire. Using validated cut off scores from the parental questionnaires 11.6% or the 3-yeare-olds had a general behaviour problem, 10-4% had problems with impulsivity, activity and attention, referred to as hyperactive behaviour. Parental rating of their child’s behaviour as hyperactive or not was confirmed by clinic tests (t 3.87, df 275, p<0.001). Atopy and allergic symptoms within the preceding 12 months were common; 19% were atopic, 33% reported wheeze, 27% symptoms of rhinitis, 19% symptoms of eczema, 0.6% reported life-threatening symptoms associated with food. All four conditions were associated with atopy. Although wheeze and rhinitis were more prevalent in children in deprived circumstances, atopy was associated with affluence. Atopy per se was not significantly associated with an increased risk of behaviour problems but children with symptoms of eczema and/or rhinitis had an increased risk of behaviour problems reported by parents, not substantiated by clinic testing. In the randomised placebo controlled cross-over trial there was a improvement in behaviour when artificial food additives were withdrawn, and significant elevations in hyperactive behaviour during the active period based on parental reports, but not confirmed by clinic tests. These effects were observed across the whole group of children, not specifically in those with prior behaviour problems, and independent of their atopic status.</p
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Children (227), aged 7–12 years, weighed and recorded all food and drink consumed for seven consecutive days. Each child completed tests of verbal and non-verbal intelligence, and was then randomly allocated to one of two groups after matching for age, sex, IQ and height. In a double-blind trial lasting for 28 d, one group received a vitamin-mineral supplement daily and the other group a placebo. On re-testing, there were no significant differences in performance between the two groups. Furthermore, there were no consistent correlations between test scores and micronutrient intakes based on the weighed records. Thus, we found no evidence that learning ability in a cross-section of British schoolchildren was limited by the quality of their diets.
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In a randomised controlled trial the effect of vitamin and mineral supplementation for seven months on performance in tests of reasoning was studied in 86 schoolchildren aged 11-13. A small, non-significant difference between the control and supplementation groups was found in a non-verbal test. The net difference in change in scores between the active and placebo groups was 2·4 units (95% Cl -1·5 to 6·3). This direction of effect was not consistently seen with three other tests of non-verbal reasoning. Vitamin and mineral supplementation does not improve the performance of schoolchildren in tests of reasoning.
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Forty-seven 6-yr-old children, under a double-blind procedure, took either a placebo or a tablet containing a range of vitamins and minerals. Before taking the tablets, and after 6 wk in one school and 8 wk in another, the children took four sub-scales of the British Ability Scale, a delayed-reaction time task, and their behaviour was ethologically described when performing a difficult task. The intelligence score of those taking the active tablets increased by 7.6 points whereas the placebo was associated with a decline of 1.7 points. An examination of the sub-scales showed that the changes were primarily of non-verbal rather than verbal measures. When faced with a difficult task they were more likely to concentrate having taken the active supplement. There was a significant relationship between the amount of sugar consumed in the diet and the improvement in intelligence scores when taking the vitamin/mineral supplement.
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Research shows that IQ is a strong predictor of student academic performance. Previous studies have found that increasing the in-take of vitamins and minerals improves non-verbal intelligence. The purpose of this study was to measure the effect of a herbal food supplement—Maharishi Ayur-Ved Student Rasayana (MA-SR)—on non-verbal intelligence. The 5-month study consisted of 34 third-grade students who were randomly assigned to either an experimental group or a placebo group. The MA-SR group exhibited a 9.83 point increase in IQ compared to 4.88 points for the placebo group. Analysis of the data indicated that a significant proportion of students in the MA-SR group (78%) compared to that of the placebo group (50%) showed an improvement in IQ which exceeded that of the test-retest effect. Additional statistical analysis further indicated that taking MA-SR improves IQ. Possible mechanisms are discussed.
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