From the Guidelines
For low magnesium levels, adults should take 500 mg/d to 1 g/d of supplemental magnesium, with magnesium oxide (MgO) being a suitable option, as it has been evaluated in clinical trials and is available over-the-counter. When considering magnesium supplementation, it is essential to note that the dose used in trials was 1.5 g/d, but lower doses of 500 mg/d to 1 g/d are often used in clinical practice 1. The bioavailability and clinical efficacy of other formulations of magnesium, such as citrate, glycinate, lactate, malate, and sulfate, are unknown, and only MgO has been evaluated in randomized controlled trials (RCTs) 1.
Some key points to consider when taking magnesium supplements include:
- Starting with a lower dose and gradually increasing as tolerated to minimize digestive side effects
- Taking supplements with food to improve absorption
- Avoiding taking magnesium alongside certain medications like antibiotics or bisphosphonates, as it can interfere with their absorption
- Being aware of potential side effects like diarrhea or stomach cramps, which may occur at higher doses, and adjusting the dose or switching to a different form if necessary
- Consulting with a healthcare provider before starting supplements, especially if you have kidney disease or take medications that might interact with magnesium, as hypermagnesemia is more likely to occur in individuals with significant renal impairment 1.
It is crucial to maintain systemic regulation of magnesium levels, which is achieved through renal excretion, and magnesium supplements should be avoided in those with a creatinine clearance of <20 mg/dL 1.
From the FDA Drug Label
USUAL DOSAGE:See attached Drug Facts Package each teaspoonful (5 mL) contains:magnesium 400 mg Active ingredient (in each 5 mL) Magnesium hydroxide 400 mg
The recommended dosage of magnesium supplement for low magnesium is not explicitly stated in the provided drug labels. However, the usual dosage can be found in the attached Drug Facts Package, which is not provided here.
- The amount of magnesium in each dosage form is 400 mg per 5 mL.
- The FDA drug label does not provide a clear recommendation for the amount of supplement someone should take for low magnesium.
From the Research
Magnesium Supplementation
The amount of magnesium supplement someone should take for low magnesium levels is not explicitly stated in the provided studies. However, the studies suggest that the bioavailability of magnesium varies depending on the form of magnesium used.
Forms of Magnesium
- Magnesium citrate: Studies have shown that magnesium citrate has higher bioavailability compared to magnesium oxide 2, 3.
- Magnesium oxide: Magnesium oxide has been found to have lower bioavailability compared to magnesium citrate 2, 3.
- Magnesium malate: One study found that magnesium malate had the highest area under the curve calculation, indicating high bioavailability 4.
- Magnesium acetyl taurate: This form of magnesium was found to be rapidly absorbed and had the highest tissue concentration level in the brain 4.
Dosage
- A study used a dosage of 400 mg of magnesium per day to saturate magnesium pools in healthy males 2.
- Another study used a dosage of 520 mg/day of elemental magnesium from magnesium oxide and 295.8 mg/day of elemental magnesium from magnesium citrate 5.
- A study used a single dose of 400 mg/70 kg magnesium administration to investigate the bioavailability of different magnesium compounds 4.
Bioavailability
- The bioavailability of magnesium can be assessed by measuring urinary magnesium excretion and plasma magnesium levels 2, 3.
- Magnesium citrate has been found to have higher bioavailability compared to magnesium oxide, with a significant increase in urinary magnesium excretion and plasma magnesium levels 2, 3.