Association Between Dietary Intake of Magnesium With Blood Biomarkers

Abstract

ObjectivesThe purpose of this study was to investigate the relationship between dietary Mg intake and concentrations of ionized magnesium (iMg+2) in whole blood and total Mg in serum. MethodsWe evaluated blood iMg+2 concentration, the physiological active measure of Mg, as well as serum Mg concentration which is a more commonly used measure of body’s status. The data study population were healthy participants (18–52 years; n = 23) who participated in three clinical visits in a magnesium supplement bioavailability study. All study participants were not taking Mg supplements within two weeks of study screening. Dietary Mg intake obtained from 3-day food records was compared with iMg+2 in whole blood and total Mg in serum concentrations using Pearson’s correlations. Ionized magnesium was measured with NOVA 8 (NOVA Biochemical, Waltham, MA), serum Mg was measured with atomic absorption spectroscopy, and dietary intake of Mg was assessed using the Nutrition Data System for Research (NDSR; University of Minnesota, MN). Results were reported as means (standard deviations) and percentages for continuous and categorical data, respectively. ResultsMean iMg+2 and serum Mg concentrations, and dietary Mg intake were 1.27 (0.07) mg/dL, 2.20 (5.0) mg/dL and 304.05 (128.77) mg/day, respectively. Results from the Pearson’s correlation coefficient showed no significant association between dietary Mg intake vs. and serum Mg (r = –0.30, p = 0.23), nor was there a significant association between dietary Mg intake and iMg+2 (r = –0.08, p = 0.74). ConclusionsOur findings suggest that iMg+2 and serum Mg concentrations may not reflect dietary Mg intake in a significant manner. Further research is needed to identify objective and accurate biomarkers that reflect dietary Mg intake, which will enable a better understanding of Mg deficiency and its association with conditions such as cardiovascular diseases, hypertension, diabetes, and chronic kidney disease. Funding SourcesAn unrestricted educational grant from New Capstone Inc., the manufacturer of ReMag®.