Whenever I see someone with insomnia, I recommend them to start taking Mg. My advice often arises a question to them that maybe taking too much Mg is not good.
I never say people should take a lot; I say that people should take Mg if they are not taking it. Overtaking can upset your stomach, and as we know over-consuming anything is not good. Oversleeping is not even good for you, so is working out too much.
Anyways, I understand your concern. You are worried about taking too much because you think that might damage your health. You’d be ok overtaking as long as you have a healthy kidney. Your kidney will get rid of excess amount if you overtake it. That is what happened to me when I first started to take it. At the beginning of my Mg journey, I took a lot of Mg unnecessarily. I say unnecessarily because your body cannot absorb a lot of Mg at once even if you are extremely deficient. That is why you get diarrhea; your body tries to get rid of excess amount of Mg.
Someone said to me that his grandmother should not take Mg because she had a kidney problem.
I disagreed. Any living human needs some amount of magnesium to be healthy including people with kidney issues, however they need to be careful how much to take. Overtaking can lead them to hypermagnesemia but they still need some Mg. Your heart does not function without Mg. You will have heart failure if you don’t have enough Mg in your body, and that is why long distance runners sometimes have a heart failure. Our body tries to maintain Mg in our heart as long as possible while the other parts in the body are deficient of Mg because without Mg in our heart, it eventually will stop the palpitation.
People with kidney problems need to be careful with sodium and medications, or even the amount of water they drink. But that does not mean that they should not get drink water at all. If you are deficient on Mg like everyone else and have a kidney problem, you would have to start with a much smaller dose than I take.
When I work out more intensely, my body uses more Mg. This is a fact because when my workout was not as intense, but still took the same amount of Mg, that is when I had an upset stomach. Intense workout depletes/uses more Mg than not intense workout.
If someone sweaty with a kidney problem works out regularly without supplementing Mg for a long time, yes he or she can have a heart failure down the line.