Oxysential

There are no established daily values for selenium. However, to maximize on its health benefits, one should take between 100-200 mcg.

Note: High doses of selenium (1000mcg or more daily) for prolonged periods may cause adverse reactions and selenium poisoning.
Yes, as long as your total daily consumption of zinc does not exceed 40 mg as it is the upper safety limit perday (You should add the total amount of zinc from all supplements and ensure that you do not take more than 40 mg /day).