From the Guidelines
For very low hypomagnesemia, the maximum amount of oral magnesium that can be taken is up to 6500 mg daily, but it is recommended to start with the recommended daily allowance of 350 mg daily for women and 420 mg daily for men and increase gradually according to tolerance. This is based on a study published in the Mayo Clinic Proceedings in 2023, which found that high doses of oral magnesium (600 to 6500 mg daily) improved symptoms in 8 out of 13 patients with erythromelalgia 1. However, it is essential to note that higher doses may cause gastrointestinal side effects such as diarrhea, which can limit absorption. Some key points to consider when taking oral magnesium supplements include:
- Starting with a lower dose and gradually increasing to minimize gastrointestinal side effects
- Taking supplements with food to improve tolerance and absorption
- Monitoring serum magnesium levels regularly during treatment, as dosing may need adjustment
- Avoiding taking magnesium supplements within 2 hours of certain medications like antibiotics or bisphosphonates, as magnesium can interfere with their absorption
- Addressing the underlying cause of hypomagnesemia is also essential for effective treatment. It is also worth noting that magnesium oxide provides the most elemental magnesium per pill but has poor absorption, while magnesium citrate, glycinate, or chloride are better absorbed options 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION: ... 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. 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 FDA drug label does not answer the question about the maximum amount of oral magnesium to take for very low hypomagnesemia, as it only discusses intravenous (IV) and intramuscular (IM) administration of magnesium sulfate 2.
From the Research
Magnesium Supplementation for Hypomagnesemia
- The maximum amount of oral magnesium to take for very low hypomagnesemia is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
- However, it is essential to note that magnesium and vitamin D are closely related, and their deficiency states may lead to several chronic medical conditions 5.
- Magnesium is crucial in the metabolism of vitamin D, and taking large doses of vitamin D can induce severe depletion of magnesium 5.
- Adequate magnesium supplementation should be considered an important aspect of vitamin D therapy 5.
- The normal serum magnesium level may still be associated with moderate to severe deficiency, making it challenging to determine the total body magnesium status in humans 5.
Hypomagnesemia and Vitamin D Deficiency
- Hypomagnesemia and vitamin D deficiency are frequent in patients with long COVID, and their correlation is associated with the number of clinical manifestations 4.
- Vitamin D and magnesium deficiency are highly prevalent in patients with asthma, and increased asthma severity is associated with lower levels of one or both 6.
- Magnesium supplementation may substantially reverse the resistance to vitamin D treatment in some clinical situations, such as chronic kidney disease 7.
- Ensuring adequate levels of magnesium is essential to obtain the optimal benefits of vitamin D supplementation in patients with chronic kidney disease 7.