Acu-Cell
https://acu-cell.com/
is a good resource for trace mineral information, & they often refer to "ratios" as being more significant with trace min's than deficiencies. More often than not, it's a surplus of one trace that antagonizes another trace (that may not even be deficient) causing problems.
Under "Mineral Ratios" in the top right section of the main page, click on the trace min's you're interested in (selenium / mang) and see what they have to say. Of course they recommend hair mineral analysis as the only way to determine which ratios are out of whack.
Personally, I wouldn't fool around with supplementing trace min's, as they are almost never deficient, but rather an excess of one is affecting the balance and function of another trace. I take mag, because it is the most common macro-mineral deficiency, and mag deficiency has a lot of ominous issues associated with it. Mag also antagonizes calcium, & calcifications (in blood vessels) are something to be avoided at all cost.
Zinc is the only micro-min I pay attention to, as Acu-Cell reports copper is almost invariably high, but I get prostate inflammation/pain when I supplement even low dose zinc, so I try to get this from dietary sources. Interesting Acu-Cell is the only site I've found that associates excess zinc with prostatitis. Zinc antagonizes copper, & copper is one micro-min I don't want to let wreak havoc in my bodkin, so I try to minimize copper and get good dietary zinc.
The other micro-min's typically take care of themselves in most folks, but it's interesting to read about the medical issues associated with imbalances. If I had a specific medical condition, I'd probably want to dig deeper into the micro's associated with my issue, but I'm pretty healthy, with no chronic health issues to speak of.
Edited by Dorian Grey, 24 October 2018 - 02:34 AM.