These terms are considered interchangeable by many in everyday use.  From an animal perspective, we may consider both to refer to what we eat.  In this resource, we restrict “food” to specifically mean the calorie-rich materials (e.g., sugars) that organisms use as energy sources.  Although producers don’t eat like animals do, they do need food in this sense (and make it themselves through photosynthesis).  “Nutrients,” on the other hand, are not calorie-rich materials but are important for other aspects of organism function.  Thinking of vitamins and minerals as nutrients may help make this distinction.  Like the components of fertilizer, vitamins and minerals are not food, but are required for healthy growth.