For example, vegans or people who eliminate all dairy foods from their diets often find it difficult to consume adequate levels of nutrients such as calcium or vitamins D — supplementation may be a logical alternative, especially if they lack exposure to good-quality sunlight. ...
But as mall visits declined and Walmart, Walmart's Sam's Club, and Costco offered more vitamins and supplements in cheaper bulk packages, GNC's business dried up. Here's how badly its same-store sales and top-line growth deteriorated over the past year. YOY growth; comps exclude internati...