Zinc is an essential trace element that has been proven to be effective for immune function, insulin regulation, thyroid health, renewal of skin cells and even vision.  We consume it primarily in our food from red meat, poultry, fish and seafood.

Morgan Chilson discusses how effective it is as a daily supplement:  http://www.newsmax.com/fastfeatures/zinc-supplement-health-benefits/2014/10/20/id/601866/