I take Solaray magnesium bio citrate capsules 400 mg X 2/day. I find that I absorb the capsules better than I do pills/tablets; at least I can tell more difference. And the formulation I take is supposed to be for "enhanced absorption".
I have a particular routine --- levo at 3:30 am, followed about an hour later with one of my blood pressure meds; 7:00 am - my cytomel and other bp med. Sometime between noon and 4:00 pm (my schedule doesn't always allow me to take them at the same time every day), a dose of calcium, magnesium, selenium, red yeast rice (for cholesterol), vitamin C. Then at bedtime, I repeat the calcium, magnesium, red yeast rice and vitamin C.
I get everything I can in capsule form because it seems that I absorb it better that way. So far Solaray is the manufacturer that I've found that does the calcium, magnesium and selenium in capsule form, but I'm not necessarily promoting them -- I'd go to another manufacturer of capsules, if I thought they would be as good.
I also am on vitamin b12 shots every 2 weeks and vitamin D every other day........
Yep, seems like I'm a "pill popper", but it works better for me and is not so hard on my stomach if I take the individual pills vs a multi; and with my medical issues, other than thyroid -- well, we do what we gotta do...........