The European food safety authority (EFSA) last evaluated vitamins and minerals for safety in 2006 and set a so-called Tolerable Upper Intake Level (UL) for each micronutrient, provided sufficient data were available. This UL reflects the maximum safe level of a micronutrient that will not cause adverse effects when taken daily from all sources for a lifetime.
| The maximum safe daily intake for magnesium is 250 mg. The safe maximum daily intake for magnesium considers only the intake of magnesium from dietary supplements and fortified foods in addition to the intake from conventional foods. |
The above safe maximum daily intake applies to children 4 years of age and older, adults, and pregnant and lactating women. It is recommended that the maximum safe daily intake for magnesium be divided into at least 2 individual doses per day to counteract any risk of diarrhea.
Excessive magnesium intake from conventional foods does not cause undesirable side effects in healthy individuals.
The NOAEL (No Observed Adverse Effect Level)-the highest dose of a substance that has no detectable and measurable adverse effects, even with continued intake-was set by EFSA at 250 mg daily of magnesium from dietary supplements and corresponds to the maximum safe daily intake.
Adverse effects of excessive magnesium intake
In general, patients with renal insufficiency (impaired kidney function) are more affected by adverse effects of excessive magnesium intake in the form of dietary supplements than healthy individuals due to decreased magnesium excretion.
In studies, soft stools and diarrhea (diarrhea) occurred in some cases at levels of 300 to 980 mg of magnesium per day. However, these complaints do not pose an immediate health risk, as the symptoms immediately subside when intake is stopped.
At high doses of 2,500 mg of magnesium daily from supplements or medicines, blood pressure drop and muscle weakness have been observed. This amount is 10 times the safe daily maximum. Very large single doses of more than 400 g (400,000 mg) can cause ileus (intestinal obstruction) and cardiac arrest. However, such amounts are not achievable through conventional foods and supplements.
