Dr. Siegel's tips for reducing risk of prediabetes Fox News senior medical analyst Dr. Marc Siegel reacts to a new study showing one in three American teenagers have prediabetes. NEW You can now listen to Fox News articles! Some surveys find that about 75% of U.S. adults have used supplements , while federal survey data shows that 58% used one in the past 30 days — but some groups should exercise caution, experts say. There are many different supplements — including vitamins, minerals, herbs,