Effects of Daily Magnesium Complex Supplementation on Body Composition in University Students

Magnesium is an essential mineral involved in numerous physiological processes, including energy metabolism, muscle function, protein synthesis, and maintenance of normal cellular function. Adequate magnesium status may contribute to the maintenance of healthy body composition and muscle-related outcomes. However, evidence regarding the effects of magnesium supplementation on body composition among healthy young adults remains limited. Therefore, this randomized, double-blind, placebo-controlled trial will investigate the effects of daily supplementation with a triple magnesium complex containing magnesium malate, magnesium glycinate, and magnesium citrate on body composition among healthy young adults.

The study will use an eight-week, randomized, double-blind, placebo-controlled, parallel-group design. Participants will be healthy adults aged 18 to 28 years with a body mass index (BMI) between 18 and 25 kg/m². Participants will be randomly allocated to either the magnesium supplementation group or the placebo group.

Participants assigned to the intervention group will receive 400 mg/day of a triple magnesium complex containing magnesium malate, magnesium glycinate, and magnesium citrate. The supplement will be administered as one capsule daily in the morning for 8 weeks (56 days) according to standardized instructions. Participants assigned to the placebo group will receive identical-appearing capsules containing microcrystalline cellulose and will follow the same administration schedule. The intervention and placebo preparations will be similarly packaged and labeled to maintain blinding.

Participants will be eligible if they are healthy adults aged 18-28 years with a BMI between 18 and 25 kg/m². Individuals will be excluded if they have chronic medical conditions requiring ongoing treatment, including cardiovascular disease, diabetes mellitus, hypertension, neurological disorders, cancer, epilepsy, renal or hepatic insufficiency, rheumatoid arthritis, multiple sclerosis, or gastrointestinal conditions such as Crohn's disease, pancreatic insufficiency, or ulcerative colitis. Additional exclusion criteria will include current smoking; use of sleep medications, magnesium-containing medications or supplements, laxatives, or hormone products; planned surgery within the next three months; participation in another clinical trial; excessive alcohol consumption; pregnancy; or breastfeeding.

Randomization will be performed using a predetermined random-number allocation sequence generated by a researcher independent of the study protocol. Participants will be assigned to either the magnesium or placebo group according to the random allocation sequence. To maintain allocation concealment and blinding, the study products will be provided in indistinguishable, unlabeled containers identified using participant numbers. Each participant will receive a sufficient supply of study capsules for the 8-week intervention period. Adherence will be assessed by counting returned capsules at the end of the intervention. Participants will be instructed to maintain their usual dietary intake and physical activity patterns throughout the study and to report any changes in medication, supplement use, or relevant lifestyle factors.

Blood samples will be collected at baseline and after completion of the 8-week intervention following an overnight fast of 10-12 hours. Serum samples will be obtained following centrifugation at 3,000-4,000 rpm for 10 minutes. Serum magnesium concentrations will be measured using the colorimetric method with VITROS Chemistry Products Mg Slides on the VITROS XT 7600 Integrated System.

Anthropometric and body composition measurements will be assessed at baseline and after the 8-week intervention. Body weight will be measured to the nearest 0.1 kg with participants wearing light clothing and no shoes. Height will be measured to the nearest 0.5 cm with participants standing barefoot in an upright position. BMI will be calculated as body weight in kilograms divided by height in meters squared. Body composition will be assessed using a TANITA SC-240 bioelectrical impedance analyzer. Body composition outcomes will include body fat mass, body fat percentage, and lean body mass. The calibration of the bioelectrical impedance analyzer will be checked according to the manufacturer's instructions before measurements.

Dietary intake will be assessed using two non-consecutive 24-hour dietary recalls, including one weekday and one weekend day. Dietary information will be collected through face-to-face interviews using standardized dietary assessment procedures. Physical activity will be assessed using the short-form International Physical Activity Questionnaire (IPAQ), with physical activity quantified in metabolic equivalent task minutes per week (MET-min/week). Information on sunlight exposure and other relevant lifestyle characteristics will also be collected. Dietary magnesium intake, physical activity, sunlight exposure, and other pre-specified baseline characteristics will be considered in the statistical analysis where appropriate.

Statistical analyses will be conducted using IBM SPSS Statistics version 26, with effect-size calculations and graphical analyses performed using R version 4.6.0. Continuous variables will be summarized using means and standard deviations, while categorical variables will be presented as frequencies and percentages. Distributional normality will be assessed using the Shapiro-Wilk test. Baseline continuous variables will be compared between treatment groups using the independent-samples t-test or Mann-Whitney U test, as appropriate, while categorical variables will be compared using the chi-square test. Within-group changes from baseline to post-intervention will be assessed using paired-samples t-tests or Wilcoxon signed-rank tests, as appropriate.

For the primary and secondary body composition outcomes, analysis of covariance (ANCOVA) will be used to evaluate post-intervention outcomes according to treatment group while adjusting for the corresponding baseline outcome and pre-specified covariates. Adjusted between-group treatment effects, 95% confidence intervals, and partial eta squared will be reported. Forest plots will be used to present adjusted treatment effects. Associations between changes in serum magnesium concentrations and changes in body composition outcomes will also be explored using Spearman's rank correlation coefficient and scatter plots. A two-sided p-value of less than 0.05 will be considered statistically significant.

The study protocol has been reviewed and approved by the Ethical Committee of Noakhali Science and Technology University (Approval No. NSTU/SCI/EC/2026/519). Written informed consent will be obtained from all participants before enrollment. Participants will be informed about the study objectives, procedures, potential benefits, and possible risks. Participation will be voluntary, and participants will have the right to withdraw from the study at any time without consequences. Participant confidentiality will be maintained by protecting identifying information and restricting access to study data to authorized members of the research team.