How much magnesium can one person take?

I just got magnesium due to a twitching eye, and while it helped with that, I didn't sleep at all last night- I have really bad nightmares sometimes and the only thing that helps is a multi vitamin but I looked on the vitamins and they already have 100mg of magnesium, and I just took 250 mg of magnesium last night around 5pm. Would it be safe now to take a vitamin? I want to sleep but don't want to overdose on magnesium somehow, does anyone know the MAX limit?

You can safely take up to 600 mg of magnesium per day but you may also need to take a calcium supplement as the recommended intake per day is something like 1,000 mg of calcium and 600 mg of magnesium (from all sources, food and/or tablets).

Calcium and magnesium are both alkaline earth metals that interact and a large excess of one creates a deficiency of the other one due to preferential absorption of the one present in a large excess. Some supplements contain both magnesium AND calcium.

I take 600 mg of magnesium daily, besides what is in my multivitamin.... its a very understated but much needed mineral.

Magnesium is water soluble, so you don't have to worry too much about too much. I don't know the max amount, but I'm pretty sure you'd be okay to take another multi, since you'll just pee out the excess.

Funny how you couldn't sleep last night. Magnesium is supposed to be really great in helping you sleep.

You need to talk to your doctor and/or a nutritionist on this. Your nightmares may well have been triggered by what you took, and you may need to change what you take.