Groups opposed to new EU rules on vitamins and food supplements have won their fight to take the matter to the European Court of Justice.
An estimated 10m Britons take vitamin supplements
The High Court in London ruled on Friday that their case could be referred to judges in Luxembourg.
The European Commission wants to tighten up the rules on food supplements from August 2005.
However, opponents say it will lead to thousands of products being taken off shelves in the UK and elsewhere.
Under the new rules, only vitamins and minerals on an approved list can be used in supplements. There will also be restrictions on the upper limits of vitamin doses.
Industry and some patient groups want the EU directive scrapped, which only the European Court can do.
Mr Justice Richards had been asked to refer the directive to the European Court on the grounds that it was unlawful and would unfairly affect millions of people, threatening both health and trade.
Agreeing to the request, the judge ruled there was "an arguable case" and the reference "is plainly appropriate and should be made as soon as possible".
The UK government had opposed the move.
Lawyers representing some of the groups told the High Court that the directive would have a "severe impact" on the sale of many "small niche" products.
Conor Quigley QC also suggested it did not have "a proper legal basis".
Andrew Lockley, a solicitor representing health food stores and manufacturers, welcomed the ruling.
"My clients are glad and relieved that their concerns about this wide-ranging directive and its effect on the health food industry and its customers in the UK have been recognised.
"They look forward to carrying on the battle to overturn the directive at the European Court of Justice."
Speaking earlier, Paoli Pestori, director of food safety at the European Commission, told the BBC's Radio 4 Today programme, the new rules would protect the public.
"The directive will not ban any product. The aim is to ensure that vitamin and mineral pills which are marketed as food supplements are safe and properly labelled."
She said there would be a list of approved products which can be sold, and in addition, individual countries could approve others - if they had a safety record put forward before 2005.
But David Hinde of the Alliance for Natural Health, which represents patients and industry, said the directive could mean thousands of products were no longer be available.
He said obtaining a safety record could cost up to £250,000 per product.
"Under the law here, you do not need to have a safety record for food supplements.
"It's a fundamental change in the law that is being proposed here."