From the Guidelines
Magnesium supplements are recommended if your magnesium levels are low, with a suggested starting dose of magnesium oxide 400-500mg daily or magnesium citrate 200-400mg daily, taken with food to minimize digestive discomfort. For better absorption, consider magnesium glycinate or magnesium malate at similar doses. Take the supplement consistently for at least 2-3 months to restore levels, preferably in divided doses throughout the day rather than all at once. Common signs of magnesium deficiency include muscle cramps, fatigue, irregular heartbeat, and numbness or tingling. Magnesium is essential for over 300 biochemical reactions in the body, including muscle and nerve function, blood glucose control, and bone health. While supplementing, increase dietary sources of magnesium such as leafy greens, nuts, seeds, and whole grains. Monitor for side effects like diarrhea, which may indicate you need to reduce the dose or switch to a different form of magnesium. If symptoms persist despite supplementation, consult with a healthcare provider for further evaluation, as recommended by recent guidelines 1.
Some key points to consider when taking magnesium supplements include:
- Starting with a lower dose and increasing as needed, especially in patients with renal insufficiency, to avoid hypermagnesemia 1
- Avoiding magnesium supplements in patients with significant renal impairment, defined as a creatinine clearance of <20 mg/dL 1
- Considering the use of magnesium oxide, as it has been evaluated in clinical trials and is often used in clinical practice, although other formulations such as magnesium citrate, glycinate, or malate may also be effective 1
- Being aware of the potential for hypomagnesemia in patients undergoing kidney replacement therapy, and using dialysis solutions containing magnesium to prevent electrolyte disorders 1
It is essential to prioritize the management of hypomagnesemia, as it can have significant clinical implications, including muscle cramps, fatigue, and irregular heartbeat. Recent studies have highlighted the importance of monitoring magnesium levels, especially in patients with cancer or those undergoing kidney replacement therapy 1. By following these guidelines and considering the individual patient's needs and medical history, healthcare providers can effectively manage hypomagnesemia and improve patient outcomes.
From the FDA Drug Label
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.
The patient with low magnesium levels should be treated with magnesium supplements. The dose will depend on the severity of the deficiency. For mild deficiency, the dose is 1 g every 6 hours for 4 doses. For severe hypomagnesemia, the dose is up to 250 mg/kg body weight within 4 hours or 5 g added to 1 liter of solution for slow IV infusion over 3 hours 2.
From the Research
Magnesium Supplements and Bioavailability
- Magnesium citrate has been shown to have higher bioavailability compared to magnesium oxide 3, 4
- Studies have demonstrated that magnesium citrate leads to a significant increase in urinary magnesium excretion and plasma magnesium levels compared to magnesium oxide 3, 4
- The solubility of magnesium citrate is higher than magnesium oxide, even in water, and it is substantially more soluble in all states of acid secretion 4
Effects of Magnesium Supplements on Arterial Stiffness
- A randomized, double-blind, placebo-controlled trial found that magnesium citrate, magnesium oxide, and magnesium sulfate supplementation did not significantly change arterial stiffness or blood pressure 5
- However, magnesium citrate increased plasma and urine magnesium levels compared to placebo, and led to a more pronounced increase in 24-hour urinary magnesium excretion than magnesium oxide or magnesium sulfate 5
- Another study aimed to investigate the long-term effects of magnesium citrate, magnesium oxide, and magnesium sulfate on arterial stiffness, but the results are not yet available 6
Magnesium Deficiency and Supplementation
- Low magnesium levels are linked to many diseases, and studies suggest that organic salts of magnesium are more readily bioavailable than its oxide or inorganic salts used for supplements production 3
- Intravenous administration of magnesium sulfate can correct hypomagnesemia, and the average rise in serum magnesium levels is higher in patients with lower estimated glomerular filtration rate (eGFR) values 7