From the Guidelines
The recommended daily dose of magnesium supplementation is 320 mg/day for women and 420 mg/day for men, with a tolerable upper intake level of 350 mg/day from supplements, as suggested by the Institute of Medicine Food and Nutrition Board 1. When considering magnesium supplementation, it's essential to choose the right type, as they offer different benefits and absorption rates.
- Magnesium oxide is common and inexpensive but has lower bioavailability (around 4%), making it less ideal despite its high elemental magnesium content.
- Magnesium citrate is better absorbed (approximately 25-30% bioavailability) and can help with constipation as a mild laxative effect, as supported by the american gastroenterological association-american college of gastroenterology clinical practice guideline 1.
- Magnesium glycinate is highly absorbable with minimal digestive side effects, making it good for those with sensitive stomachs.
- Magnesium malate combines well with malic acid and may help with muscle pain.
- Magnesium chloride has good absorption and can be found in topical forms.
- Magnesium threonate crosses the blood-brain barrier effectively and may support cognitive function. It's crucial to start with a lower dose and gradually increase to avoid digestive upset, take with food to improve absorption, and divide larger doses throughout the day. The body regulates magnesium tightly, with excess typically excreted through urine, though too much can cause diarrhea, nausea, or abdominal cramping. Those with kidney disease should consult a healthcare provider before supplementing, as they are at risk of hypermagnesemia, especially when using magnesium oxide 1.
From the FDA Drug Label
In Magnesium Deficiency In the treatment of mild magnesium deficiency, the usual adult dose is 1 g, equivalent to 8. 12 mEq of magnesium (2 mL of the 50% solution) injected IM every six hours for four doses (equivalent to a total of 32.5 mEq of magnesium per 24 hours). For severe hypomagnesemia, as much as 250 mg (approximately 2 mEq) per kg of body weight (0. 5 mL of the 50% solution) may be given IM within a period of four hours if necessary. Alternatively, 5 g (approximately 40 mEq) can be added to one liter of 5% Dextrose Injection, USP or 0. 9% Sodium Chloride Injection, USP for slow IV infusion over a three-hour period. In Hyperalimentation In TPN, maintenance requirements for magnesium are not precisely known The maintenance dose used in adults ranges from 8 to 24 mEq (1 to 3 g) daily; for infants, the range is 2 to 10 mEq (0.25 to 1.25 g) daily.
The types of magnesium supplementation and their recommended daily doses are:
- Intramuscular (IM): 1 g (8.12 mEq) every 6 hours for 4 doses (total of 32.5 mEq per 24 hours) for mild magnesium deficiency
- Intravenous (IV): 5 g (40 mEq) over 3 hours for severe hypomagnesemia
- Total Parenteral Nutrition (TPN): 8 to 24 mEq (1 to 3 g) daily for adults, 2 to 10 mEq (0.25 to 1.25 g) daily for infants 2 2
From the Research
Types of Magnesium Supplementation
- Magnesium citrate (MgC)
- Magnesium oxide (MgO)
- Magnesium sulfate (MgSO4)
Recommended Daily Doses
- The recommended dietary allowance (RDA) for magnesium is 350 mg/day for men and 300 mg/day for women 3
- For children, the RDA is 150 mg/day for 1-3 years, 200 mg/day for 4-6 years, and 350 mg/day for 7-10 years 3
- High-dose oral magnesium treatment has been used to treat chronic, intractable erythromelalgia, with doses up to 1166 mg/day 4
- For migraine sufferers, empiric treatment with at least oral magnesium is warranted, with no specific dose recommended 5