Here's another one I never would have thought of: calcium chews. In fact, I was taking these for months after my diagnosis last year, and kept thinking they were making me feel sick/dizzy/lightheaded, but I thought I was just getting paranoid. Should have known to trust myself! At some point, I glanced at the label of the Viactiv calcium chews I was taking, and to my shock there was a "may contains" statement for tree nuts.
FYI, I had to search long and hard to find calcium chews that didn't have a warning. I ended up with Walgreens brand that does have coconut, but no other warning. I still need to call to verify it's safe, but it's definitely not causing the reactions I was getting with Viactiv. This was a wakeup call to remember to check labels even when it's not "food" per se. If it's going in my mouth or on my body, I read the label.