I personally take 100mg of zinc gluconate and it helps me not to breakout.I would recommend just seeing how the 30mg of zinc does for you and if you think you need to take more you can.

Hey guys! Here's a blog entry from Dan's blog on taking zinc. 30-50 mgs per day is OK but amounts over 50 mgs should be avoided unless prescribed by a doctor.  http://www.acne.org/blog/category/zinc/

John, zinc gluconate is definitely the best form, though! Most bioavailable and easiest to absorb, so excellent choice. But I'd cut your intake in half. If you're taking zinc gluconate, your body is getting plenty of zinc. People with acne tend to be deficient in zinc, making them more prone to inflammation, which is why a supplement can help.

Hope this is helpful!