Kellogg's has defended its cereals as "perfectly safe" after authorities in Denmark banned the sale of the company's vitamin-enriched products.
Kellogg's says its cereals fall within recommended daily allowances
The Danish Veterinary and Food Administration claims that if eaten regularly, the products could damage children's livers and kidneys.
Kellogg's says its cereals are within recommended daily vitamin allowances.
In the UK, the Food Standards Agency has advised people to carry on eating cereals as part of a healthy diet.
Kellogg's had asked the DVFA if it could add iron, calcium, vitamin B6 and folic acid to 12 cereals and six cereal bars.
A spokeswoman for the DVFA said that an evaluation of the amount of vitamins and minerals consumed by people in Denmark meant that the proposed new levels would "have a high impact".
"The amounts proposed could be harmful to general health or food safety", she added.
"If they put in less than they proposed, it might be otherwise."
BBC correspondent Nicola Carslaw said that UK health campaigners had long criticised Kellogg's for marketing cereals as healthy despite high salt and sugar levels.
But there had been few concerns about vitamins because consumers are used to their products being fortified.
"In Denmark there is strong resistance and a belief that too many added vitamins can do harm", she said.
"Under EU pressure, the Danish authorities are now having to consider applications from food companies to abandon this opposition. They're clearly holding firm."
The Danes turned down proposals from Kellogg's to introduce everyday cereals enriched with the same levels of vitamins as in the UK and the rest of the world.
Nordisk Kellogg's, the Nordic branch of the food giant, said it would challenge the Danes' decision, pointing out that the rejected products were being sold legally in other EU countries.
A spokesman for Kellogg's in the UK said there were "no issues" about people eating Kellogg's cereals.
"They are well within the recommended daily allowances for vitamins and minerals and they have been well within those regulations ever since we launched 70 years ago."
The Food Standards Agency is advising people to continue eating breakfast cereal "as part of a healthy balanced diet".
The agency would be seeking further information from the Danish authorities, a spokesman said.
Earlier this year, the Consumer Association named big brand cereals, including some of those made by Kellogg's, that it said contained too much sugar, salt and fat.
Researchers compared the content of 100 popular cereals with advice from the Food Standards Agency.
It found 85 brands had "a lot" of sugar, 40 had "a lot" of salt and nine had "a lot" of saturated fat.