From the Guidelines
The best way to supplement magnesium is through magnesium oxide (MgO) at a dose of 500 mg/d to 1 g/d, as it has been evaluated in RCTs and has a beneficial effect on constipation-related symptoms. Magnesium is a naturally occurring element that plays an important role in a wide range of biological and biochemical processes, and MgO has been shown to create an osmotic gradient in the GI tract, leading to net secretion of water and electrolytes 1. When choosing supplements, it is essential to consider the formulation, as only MgO has been evaluated in RCTs, and the bioavailability and clinical efficacy of other formulations, such as citrate, glycinate, lactate, malate, and sulfate, are unknown 1.
It is crucial to start with a lower dose and gradually increase if necessary, as higher doses can cause adverse effects, such as diarrhea 1. Additionally, individuals with significant renal impairment should avoid magnesium supplements due to the risk of hypermagnesemia, and those with a creatinine clearance of <20 mg/dL should not take magnesium supplements 1. While other studies suggest that sodium picosulfate plus magnesium citrate may be effective for bowel preparation, this formulation is contraindicated in patients with congestive heart failure, hypermagnesemia, and severe renal impairment 1.
Key considerations when supplementing magnesium include:
- Starting with a lower dose (around 500 mg/d) and gradually increasing if needed
- Avoiding use in patients with renal insufficiency due to the risk of hypermagnesemia
- Considering the formulation, as MgO has been evaluated in RCTs and has a beneficial effect on constipation-related symptoms
- Taking supplements with food to improve absorption and reduce digestive discomfort
- Dividing larger doses throughout the day rather than taking all at once to minimize adverse effects.
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. 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).
The best way to supplement magnesium is through intramuscular (IM) injection or intravenous (IV) infusion, with careful adjustment of the dosage according to individual requirements and response. The usual adult dose for mild magnesium deficiency is 1 g (8.12 mEq) every six hours for four doses, which can be administered IM. Alternatively, for severe hypomagnesemia, 250 mg (approximately 2 mEq) per kg of body weight can be given IM within a period of four hours if necessary 2.
From the Research
Magnesium Supplementation
The best way to supplement magnesium is a topic of ongoing research, with various studies investigating the efficacy of different magnesium compounds.
- Magnesium citrate has been found to be more bioavailable than other magnesium preparations in some studies 3.
- Organic magnesium compounds, such as magnesium citrate and magnesium malate, may have better absorption profiles than inorganic compounds 4.
- The absorption of magnesium compounds can be influenced by factors such as the dose, galenic formulation, and individual magnesium status 4.
Forms of Magnesium Supplementation
Different forms of magnesium supplementation have been studied, including:
- Magnesium citrate: shown to increase muscle and brain magnesium levels in a dose-independent manner 4.
- Magnesium acetyl taurate: found to increase brain magnesium levels in all administered subjects 4.
- Magnesium oxide: resulted in no differences compared to placebo in terms of bioavailability 3.
Health Benefits of Magnesium Supplementation
Magnesium supplementation may have various health benefits, including:
- Preventing high blood pressure and metabolic syndrome 5.
- Reducing the risk of cardiovascular disease 6.
- Suppressing ventricular arrhythmias in patients with congestive heart failure 7. However, the evidence for these benefits is not always consistent, and more research is needed to fully understand the effects of magnesium supplementation on human health 6, 5, 7.