I'm A 62 Year-young Guy Curious About Magnesium Deficiency And

I'm a 62 year-young guy curious about magnesium deficiency and the best form of supplementation. My daily multi-vitamin offers all of 6% RDA, so I'm curious if taking additional supplements makes more sense than just trying to eat more magnesium-rich foods. Not a fan of pills, so I'm open to advice. I wonder if adding the metal to my diet would help lessen both my anxiety levels and occasional brain fog.... Thanx, -pb