ok, here's what works best for me, pretty regularly: i take 250mg of mag (along with my other supps) and one coral calcium pill with my first meal of the day (breakfast or lunch, depending) and with my evening meal i take another 250mg of mag and NO added calcium. i take an iron-free multivitamin and mineral supp (twinlab brand) and take NO added calcium apart from the coral calcium i take with my first meal. as i've stated in other threads on this site, i don't believe in that old myth about taking 2:1 calcium to mag, i do the reverse and am going to the bathroom every morning just fine, for the moment. but i also am careful about my diet and what i eat, especially at night since my bathroom time is in the early morning. for me, if i eat foods that i know will clog me up, no amount of mag will help. g-