Sales of vitamins are soaring in the United States, as out-of-work Americans, without health insurance, try to avoid costly encounters with the health-care system. Doctors aren’t all that pleased with the trend. They warn that vitamins are no replacement for those who need medical treatment. But it has been a blessing for the industry. One U.S. chain, the Vitamin Shoppe, has seen a 20 per cent surge in new customers.