Abstract
Magnesium (Mg2+) is one of the most frequently supplemented micronutrients. Due to possible gastrointestinal side effects, the European Food Safety Authority and the Institute of Medicine set the upper intake level for Mg2+ from supplements to 250 and 350 mg, respectively. Nevertheless, systematic data concerning the tolerability of Mg2+ supplements are scarce. The aim of the study was to directly compare the bioavailability and tolerability of two 500 mg Mg2+ supplements in a crossover study with duplicate determination. The different release properties were either a direct release (one phase) or a delayed release of the second half (two phases). An open-label, controlled trial with a crossover design, duplicate determination, and one-week washout phases was conducted. The participants ingested the test product after overnight fasting. Blood samples were taken at baseline and after 1, 2, 3, 4, 6, and 8 hours, and urine was collected over a period of 24 hours. The participants were on standardized nutrition during all examination days. There were no significant differences between the test products regarding 24-hour renal Mg2+ excretion and area under the curve of serum Mg2+ levels for 8 hours. Both test products were well tolerated with a very low frequency of gastrointestinal adverse effects and no significant differences between the test products. The Mg2+ bioavailability did not differ between the test products. The supplements examined had the same good tolerability. Both test products are therefore suited to enhance Mg2+ supply without relevant side effects.
Acknowledgments
The authors thank the participants who took part in this study.
Declaration of interest
The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of the article.
Funding
This study was in part funded by Merz Consumer Care (Frankfurt a. M., Germany). Study realization, data analysis, and reporting were undertaken independently from the sponsor.
Additional information
Notes on contributors
Theresa Greupner
Theresa Greupner, PhD, Institute of Food Science and Human Nutrition, Leibniz University Hannover, Hannover, Germany. Research interests: bioavailability of calcium/magnesium, omega-3 fatty acids, oxylipins.
Inga Schneider
Inga Schneider, PhD, Institute of Food Science and Human Nutrition, Leibniz University Hannover, Hannover, Germany. Research interests: bioavailability of nutrients, mineral water, glycemic response
Sandra Gellert
Sandra Gellert, PhD, Institute of Food Science and Human Nutrition, Leibniz University Hannover, Hannover, Germany. Research interests: nutrition assessment, clinical investigation, vitamin D.
Andreas Hahn
Andreas Hahn, PhD, Institute of Food Science and Human Nutrition, Leibniz University Hannover, Hannover, Germany. Research interests: nutrition and prevention, bioavailability of nutrients, omega-3-fatty acids.