PITTSBURGH -- General Nutrition Centers, Inc. said it has taken taken steps to protect its Gold Card member lists.

The information was removed from a Web site that listed it, GNC said. Suppliers have been told not to release customer data, which was how the site obtained the information, according to GNC.

Two former GNC executives, one of whom has returned to the company, owned businesses that offered lists of customers' names and personal information. One of the executives said his company got the information through a legal loophole in the agreement between GNC and its suppliers.

GNC said it does not sell customer lists, though it does make names available for one-time mailings "to customers who indicate on their application that they may receive this information."

About 4.8 million GNC customers are enrolled in the Gold Card loyalty program, which offers discounts on vitamins, diet pills and other products.