As a nurse, what concerns would you have in regard to the client’s statement?

A nurse is conversing with her patient who is elderly prior to the physician coming in to see the client. The nurse is updating her medication list. She asks the client if she is taking any over-the-counter medications, vitamins, herbs, or any other supplements so she may place them on the medication list. The client shares that she does not take anything important that the doctor needs to know about. She just takes Niacin and St. John’s wort.
a. As a nurse, what concerns would you have in regard to the client’s statement?
b. What nursing interventions would be appropriate?