Calcium is very important for breathing. have found the use of magnesium and or calcium supplements helps my breathing when asleep. Breathing gets controlled by certain mechnisms when you sleep. The acidity of the blood changes and these mechanisms repond to that to make you stop breathing or make you breathe fast. If you get a lot of apeneas, your breathing can get out of wack. You breath for a few minutes and the O2 level goes to 99 and then your motivation to breath stops(hyponea). When your O2 gets down to the high 80's then you wake up and start breathing again. The more this cycle goes on the worse it gets. I have found that taking these supplements before bed time helps keep the breathing from getting out of controll. I'm not sure how the body responds but I think that the minerals get depleted faster. Those minerals help the body regulate the acidity of the blood. This is my theory and my personal experience. I would like to hear from others to see if it works for them and too see what supplements they use. The supplement don't cure apnea they therefore is calcium needed?