Council chiefs have suspended special diet school meals until further notice after "inaccuracies" were found.
Sunderland City Council is re-checking more than 100 recipes after one non-dairy meal recipe supplied by an external dietician suggested the use of dairy-based ingredients.
Council bosses said the suspension affects up to 400 pupils who have special dietary needs - but has stressed it will have no impact on the standard service which serves more than 14,000 meals a day to children in city schools.
The authority is advising parents of children with special diets to provide their child with a packed lunch.
Michael Mordey, the senior councillor responsible for City Services, said council is not aware of any child being affected before the suspension and checks began.
"I and the City Council want to stress that this is a precautionary measure because some of the information given to us on special diets for school meals contains some inaccuracies," he said.
"Because of these inaccuracies we can't currently give a complete assurance and guarantee that all the meals for special diets meet the specified requirements.
"We are not aware of any pupils being affected and we have taken this decision to suspend special diet meals because the health and welfare of our children is our highest priority.
He added: "We apologise for the inconvenience caused. We hope that all parents appreciate it is best that we take a precautionary and proactive approach, however inconvenient.
"We are currently working with a new specialist dietician to resolve the problem, and we hope to be able to start reintroducing individual special diet meals gradually over the next few days.”
Any parent wanting to discuss their circumstances can contact the City Council School's Catering Service Manager on 0191 561 4655.