I can't say whether it boosts immunity but it helps B12 transport, reduces glutamate's toxic effects, and stabilizes milder mood issues like anxiety,depression, & agitation. i used 1/4 cap three times day once I was discharged from the ICU but started at a sprinkle. Most times, big doses aren't necessary. Its extremely rare to have toxic side effects. You'd have to have existing kidney failure, in which case a mag capsule will dump you over the edge, or maybe taking way too many capsules instead of the low dose. The toxic issues people worry about with lithium apply to carbonate. It indirectly reduces microglial activation in the brain so for most people, it would be helpful. I'll bet there are other SNPs that make a difference here that we haven't figured out so it pays to start at a little sprinkle.