Because of the research I was doing, I absorbed quite a lot of selenium into my system when in my early 20s (my socks used to smell awful, by the way). I sometimes wonder what effect it has had on me since. I have had good health over many years since then, which MDs ascribe to good genes, but still I wonder.....
Selenium is a touchy mineral, and the body needs just the right amount of it. Some people live in Se-rich parts of the country (like Wyoming) and have levels that are too high. A severe excess (selenosis) will cause a garlic odor on the breath, but I've never heard of feet. It also causes balding, but it's reversible. I don't know how long it takes the body to clear it. I just remember some things from doing some personal research some years ago.