Which brings me to another idea: to stop drinking coffee completely for a while and see how I do. Maybe I'm low on magnesium because of coffee. I drink 3-4 cups normal filter coffee in the morning, plus usually a double espresso during the day. Sounds much, but i've always had a low blood pressure and just feel sleepy without my coffee. Is coffee really depleting magnesium, or maybe something else also? And how can I keep myself awake without?