From the Guidelines
Taking more than 350-400 mg of supplemental magnesium at once can cause muscle twitching and other neuromuscular symptoms, particularly in individuals with kidney problems or those who exceed the upper limit of 350 mg daily from supplements. Muscle twitching can occur with both low and high magnesium levels in the body. Magnesium deficiency (hypomagnesemia) can cause muscle twitching when levels fall below 1.8 mg/dL in the blood, with more severe twitching and cramping occurring as levels drop further. On the other hand, excessive magnesium (hypermagnesemia) can also cause muscle issues, typically when blood levels exceed 7 mg/dL. For supplementation, the recommended daily allowance for adults is 310-420 mg, with upper limits set at 350 mg for supplemental magnesium. According to a recent study published in the Mayo Clinic Proceedings 1, high doses of oral magnesium (600 to 6500 mg daily) have been used in the treatment of certain conditions, but the author recommends initiating treatment at the recommended daily allowance (350 mg daily for women; 420 mg daily for men) and increasing gradually, according to tolerance, to avoid gastrointestinal tract intolerance, muscle weakness, flushing, hypotension, bradycardia, blurred vision, and cognitive effects associated with over-supplementation. Key points to consider include:
- The importance of gradual dose increase to avoid adverse effects
- The variation in tolerance among individuals
- The potential for magnesium toxicity, especially in those with kidney problems
- The need to monitor blood levels and adjust supplementation accordingly.
From the Research
Magnesium and Muscle Twitching
- The relationship between magnesium and muscle twitching is complex, and research has yielded mixed results 2, 3, 4, 5, 6.
- Magnesium deficiency can lead to muscle twitching, cramps, and weakness, as it plays a crucial role in muscle function and neuromuscular transmission 3, 4.
- However, excessive magnesium intake can also cause muscle twitching, although the exact mechanisms are not fully understood 2, 6.
Magnesium Intake and Muscle Twitching
- The recommended daily intake of magnesium is 310-420 mg/day for adults, but athletes or individuals with high physical activity may require more 3, 4.
- A study found that magnesium supplementation did not significantly reduce muscle cramps in older adults, but may have benefits for individuals with pregnancy-associated leg cramps 5.
- Another study found that magnesium treatment improved isometric twitch parameters and resting membrane potential in diabetic rats, suggesting a potential benefit for muscle function 6.
Adverse Effects of Magnesium
- High doses of magnesium can cause gastrointestinal adverse effects, such as diarrhea, and may interact with other medications 5.
- Muscle twitching or cramps can occur as a side effect of magnesium supplementation, particularly at high doses 2, 6.
- However, the exact amount of magnesium that can cause muscle twitching is not well established and may vary depending on individual factors, such as magnesium status and overall health 2, 3, 4, 5, 6.