Magnesium Deficiency: Prevalence, Assessment, and Physiological Effects

Abstract

Magnesium (Mg) is an essential mineral nutrient that functions as a structural component of organic molecules and cofactor in hundreds of enzymatic reactions. Mg is required for calcium and potassium ion transport, muscle contraction and relaxation, neurotransmitter release, protein biosynthesis, cellular energy production, mitochondrial functions, stabilization of cell membranes, transmembrane ion flux, genome stability, bone development, and glucose homeostasis. The intestine, kidneys, and bone are the major sites regulating whole-body Mg balance. Food, drinking water, and Mg-containing supplements are the main sources of Mg exposure. Recommended intakes for Mg have been established by scientific bodies, but values differ substantially. In North America, Mg intakes fall short of dietary recommendations for a large segment of the population. Overt Mg deficiency and marked hypomagnesemia can cause a wide range of symptoms and have serious health consequences; however, this degree of deficiency is rare in the general population. At present, the prevalence of Mg deficiency in the general population is unclear because of the uncertainty regarding Mg intakes needed for optimal health and the lack of an ideal biomarker of Mg status. Many observational studies have shown an inverse association between Mg intake and risk of diseases and health conditions, but there is a need for large, placebo-controlled, randomized trials to address the issue of causality. There is also a need for a comprehensive review of the existing evidence to determine if a reference interval for total serum (plasma) Mg concentration based on a health outcome can be established.