2500mg is a pretty high dose (imo) >> you have to understand that mineral supplementation can be tricky in that all of the minerals interact with one another. such as taking high doses of calcium will deplete magnesium, taking zinc can deplete copper etc etc. There may be a possibility that calcium may be depleted with the high magnesium intake. Other factors to consider may be sodium and potassium levels since these can affected by magnesium loading.
Go to Traceelements.com and buy Dr. Watts book, an excellent resource. I would suggest finding someone to do their testing which is worth the $, it is not expensive or invasive. If you cannot find a provider for the test, email me.