My magnesium is on the lower end of the range. My dr. has me on Magnesium Glycinate for a few years now. This form is highly absorbable and not common to cause laxative effect.
He told me it is one factor to help the heart be regular.
I think the important part is to first know your level, and with your drs. help, get the right form if needed.
Our body works in unison with vitamins and minerals, so getting a good balance is important. It is hard to do as we need to consider what we get from our food and supplements. Hard to find a supplement with simply 100% of each item, and in a good bioavalable absorbable form.
I have been using supplements per my dr. choices for 4 years and still working on balancing between food and vits.
It is possible to get too much of A if you take a high dose vitamin and eat a lot of A foods. Confusing yes.