Both of these are in multivitamin supplements (as well as on the critical minerals list for their non-health-related uses). It’s easy to confuse the two names.
This video, which I just found on YouTube and have not checked for facts, is a good introduction to the different ways manganese and magnesium may affect the human body.
And you probably will be hungry after watching it!
Featured image: andreas-eatbetter at Pixabay. Public domain.