Americans who benefit from food stamps could soon be exchanging coupons for vitamins, the Associated Press reports this week. According to the report, food stamp recipients in America could use their benefits to buy vitamin and mineral supplements under Senate legislation overhauling agriculture and nutrition programs. "You can use food stamps to buy potato chips, but you can't use them to buy multivitamins for your children,"said Seth Boffeli, a spokesman for the Senate Agriculture Committee, which recently approved the bill. Herbal supplements such as gingko biloba or St. John's wort still would not be permitted under the measure, inserted into the farm bill by the committee's chairman, Sen. Tom Harkin, D-Iowa. "Food is very important, and the food stamp program is there to ensure that people are food secure, that they're not hungry," said Lynn Parker, director of child nutrition programs for the Food Research and Action Center, a research and advocacy group. At least 22 states provide vitamin supplements to poor people under their Medicaid programs, the centre says. All states must provide prenatal vitamins. Opposition to the bill came from scientists, concerned that people will substitute supplements for nutritious food, and the produce industry that fears the plan will cut into sales of fruits and vegetables.