One of the things I have to repeat myself about the most is this:
Magnesium is required to make calcium bioavailable.
Magnesium that controls the fate of sodium, potassium and calcium in the body.
If magnesium is insufficient, potassium and calcium will be lost in the urine and calcium will be deposited in the soft tissues (kidneys, arteries, joints, brain, etc.). Magnesium and calcium complete for many of the body’s chemical pathways
Here's an old blog/podcast worth checking out or revisiting to stay on top of your muscle health -even *I* need this reminder from time to time 😉
https://lydiajoy.mykajabi.com/blog/the-magnesium-calcium-relationship-and-why-it-matters-for-your-muscle-health