From the Guidelines
Magnesium supplements come in several forms, including magnesium oxide, citrate, glycinate, lactate, malate, and sulfate, each with different absorption rates and uses. When considering the types of magnesium supplementation, it's essential to note that while magnesium oxide (MgO) has been evaluated in RCTs for its efficacy in treating chronic idiopathic constipation (CIC) 1, the bioavailability and clinical efficacy of other formulations, such as citrate, glycinate, lactate, malate, and sulfate, are unknown. Some key points to consider when choosing a magnesium supplement include:
- Magnesium oxide is less bioavailable but contains more elemental magnesium per dose, commonly used for heartburn and constipation.
- Organic salts like citrate, lactate, and aspartate have higher bioavailability than magnesium oxide or hydroxide 1.
- Magnesium glycinate is well-absorbed and gentle on the stomach, making it ideal for those with digestive sensitivities.
- Magnesium chloride absorbs well and is available in both oral and topical forms.
- Magnesium malate combines well with malic acid and may help with fatigue and muscle pain.
- Magnesium threonate is designed to cross the blood-brain barrier, potentially supporting cognitive function.
- Magnesium sulfate (Epsom salt) is typically used in baths for muscle soreness rather than oral consumption. It's also important to consider the dosing and administration of magnesium supplements, as taking magnesium with food can reduce digestive discomfort, and splitting doses throughout the day improves absorption 1. Additionally, avoiding use in patients with renal insufficiency due to the risk of hypermagnesemia is crucial 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Dosage of magnesium sulfate must be carefully adjusted according to individual requirements and response, and administration of the drug should be discontinued as soon as the desired effect is obtained. Both IV and IM administration are appropriate 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). 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 are:
- Intravenous (IV): administration of magnesium sulfate through a vein
- Intramuscular (IM): administration of magnesium sulfate through a muscle injection
- Total Parenteral Nutrition (TPN): administration of magnesium sulfate through a nutrition solution given intravenously 2
From the Research
Types of Magnesium Supplementation
- Magnesium citrate: a highly bioavailable form of magnesium, shown to increase muscle and brain magnesium levels in a dose-independent manner 3, 4, 5
- Magnesium malate: an organic magnesium compound, often used in combination with magnesium citrate as magnesium citrate malate 6
- Magnesium acetyl taurate: an amino acid-bounded compound, found to increase brain magnesium levels in all administered subjects 3
- Magnesium glycinate: an amino acid-bounded compound, often used as a dietary supplement, but its bioavailability compared to other forms is not well established 3
- Magnesium oxide: an inorganic magnesium compound, shown to have lower bioavailability compared to organic forms like magnesium citrate 4, 5
- Magnesium sulfate: often used in high-dose oral treatments, has shown beneficial effects in pain syndromes and vascular disorders, but may cause adverse effects like diarrhea 7