Dunno, better ask grz. All I know is that one cannot grow the medicinal Bear Garlic without Se and if you grow regular garlic, brocoli and cauliflower without it you don't get any Se or SeMC in your vegies.

In short ONLY properly grown vegies work against cancer the rest is as empty as Wonder bread...

from:
http://aor.ca/int/related_research/bearlic_garlic.php

The common, domesticated garlic created by millennia of selective breeding, sold in supermarket chains, is not the garlic that’s found wild in Nature. And it’s this common, domesticated garlic (Allium sativum) which is used to make the most readily-available garlic supplements – from the so-called “aged garlics,” to the reputedly high-allicin German garlic extracts, and all the way down to the indistinguishable masses of lower-cost but untested garlic pills which crowd health food store shelves. But the true, original garlic of traditional medicine and modern Science is Allium ursinum