Hi Inester7;
How much zinc a person needs to supplement daily is another tough call. ( Can't something be easy?)
Of course, diet, digestion, and medications must be considered. Typically, the RDA for zinc is 8-11 mgs. for females, and 11-15 mgs. for males.
I'm a female, but I'm finding that I need 15mgs of zinc in a supplement daily. ( absorption problems, medication, etc.)
When taking that amount, copper should also be supplemented, usually 1mg for every 10-15 mgs zinc. ( too much zinc with too little copper may increase fatigue, and possibly cause an autoimmune reaction. Too much zinc can lower cortisol. ( sorry to complicate this )
So, for now, I take the zinc alone in the afternooon/ evening. I divide a tablet, and take 7.5 mgs at a time, 2x daily. (It is really helping my sleep too.)