Magnesium C
Needed in deficiency; it does not improve performance in those with adequate intake
Citable fact
«Magnesium» — evidence level C. Dosage: 200–400 mg of elemental magnesium per day. Forms: citrate, glycinate, malate, oxide; oxide is absorbed worse but works as a mild laxative. Source: PMID 26920240, permanent link to the source in the list below.
How it works
A cofactor of more than 300 enzymes, including ATP-dependent reactions and the regulation of muscle contraction. Deficiency leads to cramps and poorer exercise tolerance.
Dosage and intake
200–400 mg of elemental magnesium per day. Forms: citrate, glycinate, malate, oxide; oxide is absorbed worse but works as a mild laxative.
In the evening, often before bed; if divided, 2 times a day. Taking it with protein food is tolerated better.
Forms
Citrate, glycinate, oxide and malate have been studied. Topical forms (bath salts, gels) have no convincing data on systemic absorption.
What is confirmed
- Correcting magnesium deficiency reduces the frequency of muscle cramps in susceptible people
- ACSM and sports nutrition position stands emphasize the importance of replacing sweat losses
- Improved performance in people without deficiency is not confirmed
- A small subjective improvement in sleep quality in some small studies
Adverse effects and limitations
- Diarrhea and cramps with oxide and high doses
- In renal failure, risk of hypermagnesemia
- Easily confused with prevention of cramps of a different origin
Interactions
- Tetracyclines, fluoroquinolones and bisphosphonates: separate by at least 2–4 hours
- Diuretics and proton pump inhibitors increase magnesium losses
- High doses of zinc impair magnesium uptake when taken together
Who must not use it
- Under 18 years: Prophylactic doses by age; high doses are not recommended.
- Pregnancy and lactation: Prescribed when indicated; self-administration of high doses is not recommended.
- kidney failure
- atrioventricular block
- myasthenia
Sources
- Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance · Thomas DT, Erdman KA, Burke LM · Journal of the Academy of Nutrition and Dietetics, 2016 · PMID 26920240
- Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations · Vitale K, Getzin A · Nutrients, 2019 · PMID 31181616
- International society of sports nutrition position stand: nutritional concerns of the female athlete · Sims ST, Kerksick CM, Smith-Ryan AE · Journal of the International Society of Sports Nutrition, 2023 · PMID 37221858
See also
Open in the app
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