NEW YORK (Dow Jones)--Shares of nutritional supplement makers climbed Monday as Sen. John McCain (R., Ariz) withdrew his support for legislation to regulate dietary supplements. "It looks like it will be an easier world to be in the dietary supplement business," said Avondale analyst Bret Jordan. "The bill would have significantly tightened regulatory requirements." In February, McCain and Sen. Byron Dorgan (D., N.D.) introduced the Dietary Supplement Safety Act of 2010 to give the U.S. Food and Drug Administration more power to oversee the dietary supplement industry amid concerns the products contain harmful, hidden ingredients. The proposal would have given...