The currency recommended daily allowance also known as the NRV (nutrition reference value) is 375mg per day for adults and because you gain a fair percentage of this from your diet (there are lots of foods that are rich in magnesium), the upper safety limit for supplementing with magnesium is 250mg a day for adults. Neutrient Magnesium provides 244 mg of highly absorbable, fast-acting magnesium, the perfect amount to top up your dietary intake without going over those all-important safety limits.