Recipe Health risk Database ERD structure
You probably want to have some risk information in your NUTRITION table.  Perhaps a text column to describe the risk and a threshold quantity column, which might be optional, to describe what is a safe and an unsafe amount.

The thing you have to decide is whether you want to try to normalize out some other information from your nutrition risk descriptions.  For example, do you want to have a MEDICAL_CONDITION table that allows risks to be categorized in terms of what type of person is at risk (e.g. diabetes, nut allergy, lactose intolerance,...)

From a design perspective, we can't answer your question about what is needed.  That depends on your business rules and what you want to achieve.  We can help with technical design questions based on specific statements of your business rules.