Hi-- I found this post by googling "magnesium intolerance" because I haven't been able to get any help with this from any of my excellent integrative medicine doctors, all of whom were stumped. I have many, many symptoms that cry out for magnesium, including insomnia, anxiety, muscle cramping, and epilepsy, but magnesium supplementation makes me worse. I've tried dozens of forms of magnesium, including IV magnesium drip, magnesium oil and homeopathic magnesium. Magnesium INCREASES my muscle spasms, so it's not just that I don't absorb it and therefore don't improve. The IV drip caused an excruciating two day muscle spasm in my calves. I get MORE agitated.
I haven't found any reasonable explanation and it's very frustrating, because every practitioner who knows anything about nutrition recommends magnesium for me.
I do take B complex, extra B6 and a multimineral/vitamin for people with neurological issues (excludes copper which is overabundant in epileptics.)
I had a test for magnesium in my cells and it was ok, as was the level in my hair. I have many paradoxical drug reactions,because I have 9 genetic variations in my liver enzymes that impact how I break down a lot of substances, but I've not found any reference anywhere to this impacting magnesium metabolism.
I'd love to pool resources and see if we can help each other figure this out!