A nurse is taking a medication history from a client who has a new prescription for levothyroxine. The nurse should instruct the client to wait 4 hours after taking levothyroxine before taking which of the following supplements?

A. Zinc is not known to significantly interfere with the absorption of levothyroxine. While it is important to consider potential interactions with any supplement, zinc does not require a specific time gap when taken with levothyroxine. B. Vitamin C does not interfere with the absorption of levothyroxine. In fact, some studies suggest that vitamin C might enhance the absorption of levothyroxine, but it does not necessitate a waiting period. C. Calcium is known to interfere with the absorption of levothyroxine. Calcium supplements can bind to levothyroxine in the gastrointestinal tract, reducing its absorption. Therefore, it is recommended to wait at least 4 hours after taking levothyroxine before consuming calcium supplements. D. Ginkgo biloba does not have a significant interaction with levothyroxine. While it is always good practice to monitor for any potential interactions, ginkgo biloba does not require a specific waiting period when taken with levothyroxine.