Vitamin suppliers and health food stores are challenging regulations that they say could see hundreds of food supplements banned from sale.

The rules, which were passed in 2002, are due to take effect across the European Union in August. Opponents say they threaten the sale of hundreds - even thousands - of common products containing nutrients and minerals. The directive lists only a few dozen vitamins and minerals, and just over 100 sources from which they were derived, for use in food supplements.