Dietary supplements are a $35 billion market that's growing at a rate of 7.6 percent. So who are the consumers driving the industry's growth? Who's taking supps, what are they taking, where do they store them in their homes, when did they start popping these pills and why do they take supplements? Here's the latest breakdown from the Council for Responsible Nutrition. The trade group conducts annual surveys that assess consumers' attitudes and behavior toward dietary supplements.