Assessing Magnesium Status: A Persisting Problem

Abstract Magnesium plays an essential role in a wide range of fundamental biological reactions. Although diets consumed by healthy Americans usually do not lead to clinically significant magnesium depletion, epidemiological and clinical studies have suggested an association between low magnesium status and increased risk of cardiovascular diseases, hypertension, osteoporosis, diabetes, and other chronic diseases. In acutely or chronically ill hospitalized patients, the prevalence of hypomagnesemia has been reported to be as high as 11%. Hypomagnesemia resulting from underlying disease can be due to decreased gastrointestinal absorption or increased renal magnesium losses. Magnesium is principally an intracellular cation. Tissue magnesium status is difficult to accurately estimate with non‐invasive measures due to poor correlations between serum or RBC or WBC magnesium levels and magnesium concentration in major tissue stores in muscle and the skeleton. At present, a comprehensive evaluation of a patient's risk of magnesium deficiency should include consideration of known risk factors and disease conditions possibly contributing to magnesium depletion, estimates of dietary magnesium intake, and clinical observations. The evaluation also should include laboratory measures of magnesium status, including analysis of both extracellular (serum magnesium) and intracellular (RBC, WBC or muscle magnesium) magnesium concentration, if available. Researchers should continue efforts to find a simple, reliable, and useful technique to accurately estimate magnesium status.