Young Ju, Ph.D.

Magnesium is an essential mineral.  The body needs magnesium to regulate many bodily functions, including muscle function, nerve function, and energy metabolism (NIH).  Association studies have found a strong relationship between magnesium status in the body and muscle performance.  Some magnesium supplementation studies have shown that magnesium may improve exercise performance (Zhang et al., 2017).  Other studies have shown that magnesium supplementation may reduce inflammation and muscle soreness after strenuous exercise (Steward et al., 2019).

The average daily recommended amounts depending on age and sex (NAS).  The average magnesium intake level of Americans is less than the recommended level.  The recommended amount in milligrams for women ages 19+ is 310-320 mg; the recommended amount for men ages 19 is 400-420 mg.

Many foods are rich sources of magnesium such as nuts, legumes, seeds, grains, green leafy vegetables, and dairy products.  Magnesium is also added to some fortified foods (USDA; Cinquanta et al., 2016).  About 30 to 40% of ingested magnesium from food is absorbed in the body.

Magnesium is also available in multivitamin/multimineral supplements and supplements that contain only magnesium.  Magnesium in these supplements is in many different forms--magnesium aspartate, magnesium citrate, magnesium lactate, and magnesium chloride that are more easily absorbed in the body.  These dietary supplements contain no more than 350 mg magnesium per serving.  Magnesium is also found in some laxatives and antacid medicines (e.g., Mylanta Ultimate Strength contains 500 mg of magnesium hydroxide).  There are effects from too low as well as too high magnesium levels as shown in the table below:

People at risk of both hypomagnesemia and hypermagnesemia should talk to their healthcare providers about how much magnesium they can safely get from food and supplements.  As always, this information is provided for your reference and you use at your own risk; you should rely on your medical professional for medical advice.

References

Cinquanta L, Cesare CD, Manoni R, Piano A, Roberti P, and Salvatori G. Mineral essential elements for nutrition in different chocolate products. International Journal of Food Sciences and Nutrition. 2016, 67(7):773-778.

NAS  National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Sodium and Potassium. Washington, DC; The National Academies Press; 2019.

NIH  National Institutes of Health Office of Dietary Supplements-Potassium  https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/

Steward CJ, Zhou Y, Keane G, Cook MD, Liu Y, and Cullen T. One week of magnesium supplementation lowers IL-6, muscle soreness and increases post-exercise blood glucose in response to downhill running. European Journal of Applied Physiology. 2019, 119(11-12):2617-2627.

USDA National Nutrient Database-Potassium https://www.nal.usda.gov/sites/www.nal.usda.gov/files/potassium.pdf

Zhang Y, Xun P, Wang R, Mao L, and He K. Can magnesium enhance exercise performance? Nutrients. 2017, 9(9):946