Why might a non-compliant diabetic patient spuriously present with elevated K+ levels? One respondent noted that she once observed a patient present with elevated K+ when tested in the morning and normal K+ in the afternoon. The cause turned out to be the patient’s daily breakfast of potassium-rich tomatoes, consumed for their anti-inflammatory properties. Given the high cost of insulin, the diabetic patient might similarly be resorting to home remedies that interfere with testing.