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. Potassium intake is not specifically important for the management of lithium therapy, though potassium levels should be monitored in some situations for general health. B. Lithium is a mood stabilizer used to treat bipolar disorder, and it is important to maintain a consistent sodium intake. Lithium levels can be affected by changes in sodium levels, as low sodium levels can increase lithium toxicity. C. Vitamin C is not directly related to lithium therapy and is not necessary for managing its effects. D. Vitamin K does not have a significant role in lithium therapy and does not impact its effectiveness or toxicity.