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Effect of Randomized Multivitamin-Mineral Supplementation on Standardized Assessment of Academic Performance in Elementary School Children
Principal Investigator (PI):
Adam Perlman, M.D., MPH, Institute for Complementary and
Alternative Medicine, School of Health Related Professions
University of Medicine and Dentistry of New Jersey
John Worobey, Ph.D. and Daniel J. Hoffman, Ph.D.,
Department of Nutritional Sciences, Rutgers University
Julie OSullivan Maillet, Ph.D., R.D., and Riva Touger-Decker, Ph.D., R.D.
Department of Primary Care, University of Medicine
and Dentistry of New Jersey
Jeffrey Smith, Ph.D., Department of Educational Psychology,
The fundamental question to be addressed in this research is whether the regular taking of multivitamins results in improved school performance as measured by achievement test scores, grade point average (GPA) and attendance in school. We propose to conduct a randomized double blind, placebo-controlled trial in order to test the impact of multivitamin-mineral supplementation on intellectual/academic performance and behavior in socioeconomic at-risk children. As nutritional inadequacies are likelier to be evident in populations of children who are socio-economically disadvantaged and therefore at-risk, children will be drawn from an urban school district in New Jersey.
Background And Significance
For the present investigation, the term malnutrition will refer to poor nutrition because of an insufficient or poorly balanced diet (www.yourdictionary.com). A long-standing body of literature has documented the negative effects of malnutrition, even mild to moderate malnutrition, on the cognitive and behavioral development of children (1,2,3,4). In response to such findings, intervention studies indicate that nutritional supplementation, whether through infant formula, preschool snacks, or school breakfast, are partially effective in offsetting the effects of malnutrition on academic performance, school attendance, and psychosocial dysfunction (5,6). Little research has been conducted on the utility of multivitamin-mineral supplements as a means for improving the nutritional status of children or their academic performance. Since cognitive function is dependent to a degree on health and nutritional status (7,8), it would be expected that at the very least, nonverbal intelligence is affected by nutritional inadequacies.
A handful of studies over the last 15 years provide preliminary evidence for the effectiveness of multivitamin-mineral supplements in raising certain aspects of intelligence. As early as 1988, Benton and Roberts (9) showed a 7.2-point increase in nonverbal intelligence for the 30 schoolchildren of the active group over the placebo after a nine-month intervention. In 1990 with a sample of 227 children, Nelson et al. (10) showed a 3.3-point increase on the coding scale of the Wechsler Intelligence Scale for Children. In the same year, Crombie et al. (11) found their active group of 43 children outperformed the placebo group by 2.4 points on a test of nonverbal intelligence. In 1991, Benton and Cook (12) reported some striking findings for a cohort of 6-year-olds tested with the British Ability Scales. Children taking the vitamin-mineral tablets showed an increase of 7.6 points, while those who took the placebo showed a 1.7-point decline.
With a relatively small sample of 26 school-age children, Schoenthaler et al. (13) showed a six-point increase for the active group over the placebo after three months. The Schoenthaler research group has been fairly active in this line of investigation. For example, in 1999 Schoenthaler and Bier again demonstrated the efficacy of vitamin-mineral supplements by reporting a 3.2-point increase in nonverbal intelligence scores among six to seventeen-year-old children across 15 public schools (14). More intriguing were their results from another study. In comparing the behavioral records of the 80 six to eleven-year-olds whom they randomly assigned to either vitamin-mineral supplement or placebo, the 40 children in the vitamin-mineral treatment group had lower rates of being disciplined by school authorities, and fewer indications of antisocial behavior (15).
Despite the convergence of these findings, these studies, as well as other investigations that have attempted to replicate their findings, have been criticized on numerous counts (16-18). Among the identified weaknesses that a number of the studies possess are: faulty random assignment; non-representative samples; no assurance of blindness to treatment; inadequate assessment of nutritional status; failure to assess compliance; reliance on a single or invalid measure of nonverbal intelligence; group means affected by extensive gains in a few subjects; insufficient statistical power; and an absence of school performance measures. Further complicating matters, studies vary by adequacy of their sample size, multivitamin-mineral formulation and dosage, and duration of the intervention. The lack of a validated underlying theory as to the mechanism by which multivitamin-mineral supplements would boost intelligence or academic performance is also a notable weakness of the literature on the whole (19).
In a recently published study on multivitamin-mineral supplementation and intelligence in school children, again, by the Schoenthaler group (20), a 50% RDA dose was employed despite evidence exists that a 100% RDA dose may be the most effective. The study resulted in a 2.5-point increase in nonverbal intelligence by the active group relative to the placebo. However, the researchers failed to assess nutrient status.Thus the studys authors could only suggest that 19% of the sample children who displayed the 16-point net gain (and thereby lifted the active groups mean nonverbal intelligence to significance) were malnourished. In light of these assorted deficiencies and inconsistencies, it is far from clear as to how effective the use of multivitamin-mineral supplements may be in improving the intellectual development or academic performance of children who are at nutritional risk.The lack of definitive research has led to the development of guidelines from key professional associations such as the American Dietetic Association and the American Academy of Pediatrics that do not include recommendation of routine multivitamin administration.
Limitations to this line of research notwithstanding, in 1999 The Healthy Foundation (THF) was founded as a non-profit organization committed to providing at- risk populations with basic nutrients through supplementation. Currently THF distributes daily multivitamin-mineral tablets to thousands of adults and children at-risk for nutritional deficiencies in over thirty-five states and at more than a hundred sites. Anecdotal evidence, collected by THF over the last several years, suggests that giving socio-economically disadvantaged and therefore at-risk children a daily multivitamin at 100% RDA can lead to improvement in academic performance, general health and behavior.
Research Design And Method
With one in five American children projected as nutritionally at-risk (13, 15), we propose to randomly select approximately 1,600 fourth-grade students for this study from the 3,412 current Newark fourth-graders. By restricting the population to fourth-graders in this initial study, confounding variables such as a wide range of ages, prepubescent and postpubescent considerations will be limited. This will also allow the Assessment of Skills and Knowledge (ASK), New Jerseys new state test developed as a tool to measure how well students are gaining the knowledge and skills deemed necessary for success in life, to be used as the primary outcome measure. Beginning in 2003, in response to the No Child Left Behind Act, this standardized test will be given at the end of May to both third (ASK3) and fourth (ASK4) grade students. Subjects will not be excluded based on gender or race. Subjects taking a multivitamin-mineral supplement at the time of pre-screening will be excluded from participation. Subjects who did not complete the ASK3 will also be excluded. Given that our hypothesis does not presuppose that the children are malnourished but merely requires they be at-risk based on socioeconomic status, we do not believe that nutritional screening is required for all subjects. Diet quality and nutritional intake will be assessed on a subset of subjects through the use of the Block Food Frequency Questionnaire (BFFQ).
Commitment will be obtained from the school system to partner on this project.In order to recruit subjects, a flyer will be sent out over the summer and at the beginning of the school year explaining the study and soliciting participation. In addition, the Principal Investigator (PI) or representative will be present at Parent Teacher Conferences in order to answer questions and support recruitment. Dinner will be provided to parents in order to encourage their attendance. Once subjects have been identified, informed consent will be obtained from the parents as well assent from the children. The subjects will then be pre-screened to determine eligibility. Eligible subjects will be randomly assigned to receive either multivitamin-mineral supplement or placebo using a blocked randomization schema for each participating school. This will ensure that each school has an equal number of students assigned to the treatment choices, in case schools show variation in response. The intervention will begin in December 2003 and will last for approximately a sixth-month period prior to the scheduled standardized testing at the end of May 2004.
The intervention will consist of multivitamin-mineral supplements or placebos distributed to subjects once a day via the classroom teacher or research assistant in a double-blind manner. See Addendum 1 for multivitamin-mineral content. Each subject will have a daily envelope with his/her name on it and will ingest two tablets during morning snack. Supplements/placebos will be given Monday through Friday and will not be distributed during weekends or holidays. Pill counts and student attendance records will be used to confirm compliance, as blood levels are unrealistic to obtain as a part of this experimental design. Noncompliance should be limited through the use of teacher or research assistant administration of pills.
As noted above, the intervention will last for approximately six months with post-intervention administration of the standardized test occurring at the end of May 2004.ASK3 and third grade GPA will be used as baseline measurements. Outcome measures will include the ASK4 as well as GPA, instances of tardiness, absenteeism and incidents of misbehavior based on school record review from Spring 2003.Height and weight will be measured by research staff and subsequently used to determine body mass index (BMI) both pre and post intervention. The BFFQ will be utilized at both initiation and termination of the intervention on a subset of 600 students, or 300 per group. Parents will be given a monetary incentive to assist their child with the completion of the questionnaire. For one year following the study, children in both groups will be offered multivitamin-mineral supplements free of charge to be taken home and administered by their parents/caregivers. In addition, teachers will be given a thank you gift for their classroom as incentive for their participation.
Even though more sophisticated statistical techniques such as multiple regression analysis and analysis of variance will be employed to look at subtle questions in the data, the basic analysis involves an analysis of covariance with two groups. Most simply stated, the hypothesis under consideration is: multivitamins result in improved test scores, grades, and school related behavior. Each measure will be assessed prior to the beginning of the study and again at the conclusion of the study. Each pre measure will serve as a covariate for its respective post measure.
To look at the likelihood of the proposed research finding a significant result if there are true differences attributable to multivitamins, a power calculation needs to be performed. Following Cohen (21) and Winer (22) the size of a finding considered to be educationally important was estimated. In this case, it is important to be conservative in order to be able to find even a small difference if one exists. Thus, a small effect size of 0.2 standard deviations was used as a standard. Using an alpha level of .05, approximately 435 students will be needed in both the control and treatment groups in order to have a 90% chance of rejecting the null hypothesis of no treatment effect. The N will be increased to 1,600, or 800 students per group, to allow for a 45% attrition rate.
The BFFQ will be used to assess the nutritional quality of the diets of a randomly selected subset of subjects. The BFFQ is a validated instrument that estimates both food group and specific nutrient intake (23,24). The BFFQ is also available in Spanish. In a secondary analysis, analysis of covariance will examine the relationship between multivitamin-mineral supplements and diet quality.
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Risks to the Subjects
Human Subjects Involvement & Characteristics:
Participants will be comprised of approximately 1,600 fourth grade (ages 9-10 years) students from the school system, from a target population of approximately 3,400 fourth graders from 60 elementary schools. Students at participating schools will be approached as described below.All children will be considered for participation, excluding those who did not complete the Assessment of Skills and Knowledge (ASK3) exam at the completion of the third grade, as this serves as the baseline measurement for the study as well as those currently taking a multivitamin-mineral supplement.
Upon return of parental/guardian informed consent and student assent forms, participating students will be randomly assigned to the multivitamin/mineral supplementation or placebo supplementation daily regimen. Demographic information will be collected on each participating student. Per protocol, participating teachers or research assistants will distribute daily, packages of supplements or placebos during their scheduled morning snack. This regimen will continue for six months or by the end of the school year (May 2004), when the ASK4 (Assessment of Skills and Knowledge) exam is given to all fourth graders. On a random subset of participants (n=600) a one-time diet quality and nutritional intake assessment using the Block Food Frequency Questionnaire (BFFQ) will be conducted. School records will be abstracted for third grade performance on the ASK3 exam, their GPA and school performance to serve as baseline measurements and again upon the completion of the ASK4 exam for fourth grade school performance. Information will be coded and analyzed in mass using treatment arm assignment (multivitamin versus placebo) as the major grouping factor. No analyses identifying students is necessary or warranted for this supplementation regimen comparison.
Sources of Materials:
Materials to be collected will be self-reported demographics, height/weight, behavioral and nutritional information from consenting participants and their school performance records for years three and four.
No potential risks are expected from the daily ingestion of a multivitamin/mineral supplement. In addition, no potential risk or harm to the student is expected from the demographic/behavioral questionnaire, food-frequency survey completion, or the sharing of limited school records demonstrating academic performance in grades three and four.
Adequacy of Protection Against Risks
Recruitment and Informed Consent:
After IRB and School Administration approval, investigators will approach elementary schools in the system for participation. Principals, teachers and other school administrators will meet with investigators to learn the study objectives, school and student expectations, benefits and risks. Cooperating elementary schools, through their teachers, will send out fliers during the summer to fourth graders and their parents soliciting participation at the start of the school year (September 2003).In addition, presentations by the Principal Investigator and study team at Parent-Teacher Conferences at the start of the school year will help answer questions and support recruitment. At the start of the school year, with the assistance of participating teachers, the Principal Investigator and study team will distribute to all students information on the protocol and the informed consent documents to share with their parents/guardians. Parents/guardians and students can review the informed consent and study materials and can contact the study investigators for additional information. For those parents who read at below the sixth grade level, arrangement will be made to read the documents to them. Signed UMDNJ IRB approved consent forms by the parent demonstrating informed consent and assent by the student, as per 46CFR Subpart D, will be returned to teachers and study staff as interest in participation.
Protection Against Risk:
Student confidentiality will be maintained using study ID numbers, securing surveys in locked cabinets and dedicated computer. Teachers will receive name-labeled envelopes with the appropriate supplement, while all other interactions and data collection efforts will use the unique study ID number. Names will be omitted from any study files. Only identified study staff and investigators will have access linking student name with ID number. All identified staff and investigators will have completed Human Subjects Protection training in compliance with UMDNJ policy and OHRP policy.
Potential Benefits of the Proposed Research to the Subjects and Others
Potential benefit of participation to the study participants include six months of multi-vitamin/mineral supplementation during the treatment phase for half the children, plus 12 months of continued multi-vitamin/mineral supplementation after the study closes to both the vitamin and placebo arms provided free of charge by the sponsor.
Importance of the Knowledge to be Gained
Potential benefit to others include determining whether inexpensive daily vitamin supplementation can enhance school performance, as measured by the ASK4, GPA, and other measures of student performance. Results from this study could help identify inexpensive public health tools in enhancing student performance, reducing absenteeism, tardiness and measures of school misbehavior.
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To view Addendum 1, click here.