I thought this would help in knowing the different forms of Magnesium better.... The excerpt is from the following website:
http://articles.mercola.com/sites/articles/archive/2012/12/17/magnesium-benefits.aspx
Magnesium glycinate is a chelated form of magnesium
that tends to provide the highest levels of absorption and
bioavailability and is typically considered ideal for those who are
trying to correct a deficiency
Magnesium chloride / Magnesium lactate contain only 12 percent
magnesium, but has better absorption than others, such as magnesium
oxide, which contains five times more magnesium
Magnesium carbonate, which has antacid properties,contains 45 percent magnesium
Magnesium citrate is magnesium with citric acid, which has laxative properties
Magnesium oxide is a non-chelated type of magnesium, bound to an organic
acid or a fatty acid. Contains 60 percent magnesium, and has stool
softening properties
Magnesium sulfate / Magnesium hydroxide (milk of magnesia) are typically used as a laxative. Be aware that it's easy to overdose on these, so ONLY take as directed
Magnesium taurate contains a combination of magnesium and taurine, an
amino acid. Together, they tend to provide a calming effect on your body
and mind
Magnesium threonate is a newer, emerging type of magnesium supplement
that appears promising, primarily due to its superior ability to
penetrate the mitochondrial membrane, and may be the best
magnesium supplement on the market