Improving diagnosis and treatment of hypomagnesemia

Abstract

Magnesium is one of the most abundant cations in the body and acts as a cofactor in more than 600 biochemical reactions. Hypomagnesemia is a highly prevalent condition, especially in subjects with comorbid conditions, but has received less attention than other electrolyte disturbances. This review will discuss magnesium physiology, absorption, storage, distribution across the body, and kidney excretion. After reviewing the regulation of magnesium homeostasis, we will focus on the etiology and clinical presentation of hypomagnesemia. The role of laboratory medicine in hypomagnesemia will be the main purpose of this review, and we will discuss the laboratory tests and different samples and methods for its measurement. Although free magnesium is physiologically active, total serum magnesium is the most commonly used measurement in laboratory medicine and is apt for clinical purposes; however, it is not appropriately used, and many patients with hypomagnesemia remain undiagnosed and not treated. Using information technologies, laboratory medicine can largely improve the diagnosis and treatment of hypomagnesemia through the design and establishment of automatic demand management and result management interventions by acting in the first and last steps of the laboratory cycle, test requests, and actions taken after test results, to unmask patients with hypomagnesemia and improve the number of patients undergoing treatment.

Zinc, Magnesium and Vitamin K Supplementation in Vitamin D Deficiency: Pathophysiological Background and Implications for Clinical Practice

“…The primary nutritional sources of Mg are the following: whole grains, dark green vegetables, legumes, nuts, seeds, and seafood [ 21 , 22 ]. In the small intestine, only around 30% of the total dietary Mg is absorbed; however, in the case of deficiency, increased absorption may occur through passive diffusion or a saturable transport mechanism.…”

“…The potentially beneficial impact of Mg on glucose and lipid metabolism, innate and adaptive immunity, and the nervous system deserves particular attention [ 20 , 21 , 24 , 25 , 26 ]. A deficiency of Mg is associated with headaches, hyperemotionality, generalized anxiety, insomnia, asthenia, depressive states, muscle weakness, numbness and cramps, exacerbations of bronchial asthma, increased risk of stroke, progression of diabetes mellitus and congestive heart failure, worse control of arterial hypertension, higher risk of cardiac arrythmias, alterations in blood lipids and progression of atherosclerosis, severe forms of infectious diseases, long-term COVID-19 syndrome, increased risk of cancers, and many other illnesses [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”

“…On the other hand, VitD could itself impact Mg metabolism. The majority of Mg is absorbed regardless of VDR or VitD; nevertheless, calcitriol can increase Mg absorption in the gut by upregulating intestinal VDR, and this contributes to maintaining Mg homeostasis [ 19 , 22 , 27 , 28 ]. Interestingly, VitD can increase renal Mg excretion and therefore decrease Mg retention [ 29 ]; possibly, this is realized via PTH suppression (by calcitriol), since PTH contributes to renal Mg reabsorption [ 27 ].…”

“…Nevertheless, in clinical practice, the serum Mg levels usually serve as an indicator of Mg status [ 27 , 30 ]. Mg 2+ serum levels of 0.7–1.1 mmol/L (or of 0.75–0.95 mmol/L, as recommended by others) are considered “normal”, and serum Mg 2+ values less than 0.7 mmol/L are generally considered as hypomagnesemia [ 19 , 22 , 23 ]. It was suggested that for better Mg status assessment, the renal Mg 2+ excretion should also be evaluated.…”

“…Serum Mg 2+ levels below 0.82 mmol/L and Mg 2+ urinary excretion of 40–80 mg/day can indicate Mg deficiency [ 23 ]. Other methods, e.g., the Mg load test, total RBC Mg assay, ionized RBC Mg assay, isotopic analysis of Mg, and intracellular electrolytes and magnesium test, are rarely used due to their high cost and/or limited diagnostic usefulness for certain patient groups [ 22 , 27 , 28 , 31 ].…”