Elle,
Personally I like Asporotate..and Malate for Fibromyalgia combined with Malic Acid

But, if you really dig down on minerals and check out the research, the form is not really the concern, it is the dosage that matters especially for calcium and magnesium.

Here is a no nonsense article by the governing body on Supplements..as you can see Mag Oxide, which happens to be the most concentrated and least expensive of all magensiums seems to be king of all magnesiums.

In my experience though not everyone absorbs it well..so I switch people to Asoprotate..but Magnesium Oxide powder is a great deoderant and it is dirt cheap..2lbs for like $14

As I continue to do this supplement thing, what really matters is getting enough of a dose of a compound with least amount of tablets for the best price..

And Mag Oxide seems to fit all of this.

Look alot of companies need to sell their new fangled forms of Magnesium or any other nutraceutical, so they market it as having better "solubility" and being more "bioactive".

The truth is alot of thee companies pay to have these "tests" done and are using methods generally not accepted by the scientific community.

So experiment with oxide before you have to pay more and take more, tablets of a more "bioavailable" magnesium

http://dietary-supplements.info.nih...s/magnesium.asp