Adding to this thread on Magnesium. There are several different forms of Magnesium and are absorbed differently by the body.
Below is a link describing each one and what form is best to take depending on need:
https://drnibber.com/understanding-different-types-of-magnesium/
I take Magnesium Taurate because it is easily absorbed by the body and releases taurine which is important for the heart.
https://www.austinchronicle.com/columns/2006-01-27/329491/
Magnesium citrate is another good form of Magnesium that I take sometimes.
Magnesium oxide is least bio-available (you have to take a lot of it) and tends to move through the colon easily. It is this form which leads to diarrhea in high doses and is used in laxatives. I stay away from it for that reason. It is also the form you tend to see on store shelves. Read the label closely so you don't buy the wrong magnesium.
I typically take 250 - 500 per day split between morning and evening. Magnesium is a great sleep aid when taken just before bed time. Taken first thing in the morning, magnesium reduces heart stress (and lowers heart attack risk): I also take it on an empty stomach so it doesn't interfere with other nutrients.
http://drsircus.com/cardiovascular/magnesium-the-ultimate-heart-medicine/
As TKI's deplete the body of magnesium more than normal - I wonder why oncologists don't recommend magnesium to their patients along with their TKI. My doctor suggest that I do and that's when I began to take it.