Specification: Acceptance criteria

Dear All,

Does anyone know the guidance or regulation (FDA, EU, WHO, USP…) for setting the specification in regard of acceptance criteria for dietary supplement (food supplement)?

We are manufacturing the dietary supplement as tablet dosage of multivitamin that was extracted from plants. As I referred to USP for multivitamin tablet with acceptance range from 90 - 150% of claimed label. Now we want to extent the lower limit from 75 to 150% but wondering about regulatory compliance?

Thank you very much