A mineral supplement I've taken in the past includes 10mg zinc and 1mg of copper. Thus, the amount of zinc is not at the "higher than 50mg" level that can cause a copper deficiency because of interference with bioavailability (1). This is exactly the 10:1 ratio as suggested to avoid any copper deficiency (2). Someone did his/her homework.
1. http://lpi.oregonstate.edu/infocenter/minerals/zinc/
2. http://www.pccnaturalmarkets.com/health/2934002/
