I started taking magnesium about a week ago as recommended by my doctor. We did one of those rbc tests and saw that it was very low. I wanted to start off with a low dose of 150 and work my way up. Ever since I started taking it my heart rate has decreased which is great because before it was always around 125.. now it's around 60-70 bpm. I also noticed that the tension I have in my upper shoulders and neck started going away. I know magnesium is supposed to help relax your muscles and heart, however I feel very uncomfortable with how it. The first few times I took it my bp went uncomfortably low to around 80/60. It's now stabilized around 105/60. I also feel like my breathing has become more shallow and sometimes when I'm trying to fall asleep I'll be jolted away because it feels like my breath caught (if that makes sense?). It feels like my heart beat has become a lot weaker? Has anyone else experienced this or am I just crazy haha I also take a b12 complex, omega 3, iron, and glutamine if that matters. The reason I'm not taking calcium along with the magnesium is because my calcium was already high.