Can i take magnesium oxide?

Yes: Do not take if you have severe kidney failure because the magnesium levels could build to toxic ranges. Also do not take if you have diarrhea because it will worsen your symptoms. If you have a low serum magnesium and need more than 800 mg a day consider taking mag protein plus 133 mg instead. It has more available magnesium and is much better tolerated. It is also over the counter.