Magnesium
Magnesium is often low in those with diabetes, and renal clearance may be higher in settings of elevated glucose (1). In one study of those at high risk for developing diabetes, individuals with higher intake were less likely to progress to diabetes than those with lower intake (2). This inverse relationship between magnesium intake and incidence of DM2 was confirmed in a meta-analysis (3).
Supplementing with magnesium may improve glucose control by several mechanisms (4). While magnesium supplementation has been associated with improved glucose tolerance, it should be noted that not all trials have been positive. One meta-analysis of 9 randomized control trials found it improved fasting blood sugars and HDL values, but did not significantly improve HbA1C over 12 weeks of use (5). In those studies, formulation and dosing varied. Focusing on individuals that are deficient may provide further information, however serum levels of magnesium are a poor marker of actual intracellular level due to the body’s efficient maintenance of homeostatic levels. Some feel that RBC Magnesium may be a more accurate measure.
Magnesium is found in dark green leafy vegetables, nuts, whole grains, and coffee.
Magnesium, which has a positive charge, is always linked with an anion. Its absorption by the body is very different depending on what it is combined with. Magnesium oxide, one of the most widely available combinations is poorly absorbed. Magnesium glycinate is one of several that are well-absorbed.
Common doses are 200-800mg daily. The most common side effect of magnesium is diarrhea, which is dose dependent and will resolve by decreasing the dose.
Because those with renal failure have impaired magnesium clearance, caution should be used in those with renal disease.
1. Djurhuus MS, et al. Hyperglycemia enhances renal magnesium excretion in type 1 diabetic patients. Scand J Clin Lab Invest 2000; 60(5):403-409.
2. Lopez-Ridaura R, Willett WC, Rimm EB, et al. Magnesium intake and risk of type 2 diabetes in men and women. Diabetes Care. 2004;27:134-140.
3. Larsson SC, Wolk A: Magnesium intake and risk of type 2 diabetes: a meta-analysis. J Intern Med. 262:208-214 2007.
4. Paolisso G and Barbagallo M. Hypertension, diabetes mellitus and insulin resistance: The role of intracellular magnesium. Am J of Hypertension, Mar 1997;10(3):346-55.
5. Song Y, et al. Effects of oral magnesium supplementation on glycemic control in type 2 diabetes: A meta-analysis of randomized double-blind controlled trials. Diabet Med Oct 2006; 23(10): 1050-6.