I just had an interesting conversation with Sherridon Stock. He's a pharmacologist turned naturopath based in Kent. He confirmed to me what you said Tina about liq mag chloride being difficult to absorb partly due to it being in water and partly as it's inorganic. I did find this surprising as I noticed I was feeling physically relaxed after taking it but obviously I'd need a red cell mag test to confirm whether it really was being absorbed into the cells.
Being an inorganic form means it reacts and competes with other inorganic minerals and hence decreases absorption unless you pre-ligand it (combine with amino acids).
We absorb mag best from food as that's how primitive man would have absorbed it...through nuts, leaves etc ie organic form. We're built to only absorb 10% inorganic mins from water. He considers citrate to be the best (I've heard that many times before). Aspartate is another good form. Interestingly, he didnt consider glycinate to be particularly well absorbed but its obviously helping Amanda and others.
He did a lot of research into magnesium 10 yrs ago and developed his own concoction which I have taken myself but didnt take it long enough due to the cost (about £11 for 60 caps so its expensive if you're taking 3-4 a day). It's a combination of 3 organic mag salts....citrate, EAP2 and phosphoserine. He has found this to be very well absorbed. You could say he would say this as he's selling it. Unfortunately he said due to the EU regs, its likely to end up on the not allowed list as from 2008. I may consider trying this again.
He said the more insulin resistant/glucose intolerant you are the harder it will be for you to absorb mag into the cells as insulin is required for this process. This is obviously a complex balancing process requiring lots of nutrients eg chromium.
He referred to a guy called Dowson (sp?) who first started the mag injections who stressed the importance of selenium in helping mag get into the cells. Stock himself emphasised other fat soluble antioxidants (vit E, carotenes) to help with this to counteract the damage done to the magnesium pump by free radicals, which hinders absorption.