Generally, foods are carved out of the definition of drugs, but arguably, yeah. In fact, the reason why cured meats are considered bad is that their nitrates can react with stomach acid to form carcinogenic substances. Are there any substances that people ingest that aren’t food or drugs?
Depends on how you define food. Vitamins are organic molecules that you absolutely need to survive but don’t get digested by your body. What they do is allow your body to digest the things that you do use for building blocks and energy, like sugars, proteins, and fats.