A nurse is teaching a client who has a new prescription for lithium to treat bipolar disorder. The nurse should instruct the client to ensure an adequate intake of which of the following dietary elements?

A. Vitamin K intake is important for clients on warfarin, not lithium. B. Sodium levels directly affect lithium excretion. Low sodium intake can cause lithium retention and toxicity. Clients should maintain a consistent and adequate sodium intake to help prevent lithium toxicity. C. Vitamin C does not have a direct interaction with lithium. D. Potassium is important for cardiac function, but it is not directly related to lithium therapy.