200 mg of zinc sulphate a day would not be a dose for anyone with a sensitive stomach. He would be lucky to get by with 10-15mg of the zinc sulphate form at a time. New chapter or megafood zinc(cultured vitamins) would be the easiest on the stomach and with these brands might be able to take a little higher dose than 10-15mg. I would be careful with any other brands as it might not take much to upset his stomach. High doses of zinc for long periods of time can cause copper imbalnces so I would be careful with that.