The court said that member states can require traders to apply for permission to market imported products but only on the grounds of risk to public health.
Foods with added nutrients commonly marketed in much of the European community have not been shown to present any danger.
The Commission's case against France, dating back to January 2000, involved complaints from a German maker of vitamin-enriched confectionery and a supplement business prevented from selling L-carnitine supplements.
L-carnitine is permitted across the European Union and has recently been approved in the non-hygroscopic form, L-Carnitine L-Tartrate, for inclusion on the Parnuts nutrients list. It is not, however, included on the list of vitamins and minerals allowed by the European regulation on fortified foods, making its status unclear.
The Court said that national legislation requiring prior authorisation of foodstuffs with added nutrients is not contrary to the free movement of goods as long as the procedure is readily accessible and completed within a reasonable time. If inclusion is refused, this must be only on the grounds of a real risk to public health and it must be possible to challenge the refusal before the courts.
But regarding France's requirements the court said: "The authorisation procedure is not readily accessible, not transparent as regards the possibility of appeal to the courts and is subject to unreasonable delay."
France cannot prohibit confectionery and vitamin-enriched drinks, as well as food supplements and dietary products containing L-tartrate and L-carnitine, on the sole ground that they would increase the usual intake from an already sufficiently varied diet and that there is no nutritional need for them, said the court.
"The case confirms the basic prinicple that there should be no derogation to free movement of goods unless based on public health grounds," Thierry Dieu, spokesperson for the European food and drink industry association CIAA, told NutraIngredients.com, adding that it created a precedent.
But France's ban on the energy drink Red Bull was not judged illegal because French scientists have stated in an opinion that its high caffeine content poses real risks to public health if consumed to excess and the Scientific Committee on Human Nutrition has also filed an adverse opinion on energy drinks.
The court also heard a similar case against Italy yesterday, filed by the Commission after it received a complaint from a British maker of energy bars and sports drinks.
It was decided that the Italian government had not shown any alleged risk to public health from the products and its prior authorisation procedure made the marketing of such foods more difficult and expensive.
France and Italy will have to remove the prior authorisation procedure before companies can benefit from the ruling.