Most of this information is taken from an article from Wise Traditions:
Magnesium is safe to take since it will be absorbed depending on the deficiency and if you take too much you will get loose stools. If you are really deficient and most people are the following ways to get magnesium can be used. People have had great results with using the first 5 listed below in concert.
-magnesium citrate and magnesium malate- fairly well absorbed (esp. in powdered form added to water) divide dosage during the day- early morning and late afternoon. If you cannot overcome laxative effect try magnesium taurate and magnesium glycinate. Dosage recommendations 3-10mg per lb of body weight.
-homeopathic magnesium-- magnesia phosphorica 6x (mag phos) will help eliminate or reduse loose stools when taking magnesium supplements- so you can absorb it better. This remedy is also used for muscle spasms and cramps.
-ionic magnesium in liquid form, by Trace Minerals Research. This is reduced concentration of sea water form Great Salt Lake with sodium reduced. One teaspoon= 400 mg of magnesium. You can add a few drops to soups and water and such or add to your smoothies.
-Epsom salt baths (magnesium sulfate) eases muscle aches and pains and helps detox. Or magnesium chloride for baths.
-magnesium "oil"--not really an oil, you apply it topically gets absorbed in next to intravenous magnesium this gets you the greatest amount of magnesium absorbed. Your magnesium levels will be restored in weeks rather than months.
-intravenous magnesium- for acute asthma attacks, onset of myocardial infarction.
Please see other posts on this blog on why magnesium is good for you. Although the last article from Wise Traditions is the most thorough, you can borrow my copy if you know me. I will post an overview in the future.