Tea and coffee as the main sources of oxalate in diets of patients with kidney oxalate stones.

We analyzed nutritional habits of 22 stone formers with special regard to oxalate content as one of the main nutritional lithogenic factors associated with kidney stones. Daily dietary oxalate intake was 354 +/- 261 mg and 406 +/- 265 mg in men and women respectively. These values were much higher than those found by other researches. The main sources of oxalate in diets were regular tea and coffee (80-85%). Only 15-20% of oxalate was derived from other plant foods. Patients did not adhere to high fluid diet and, what is more, as common beverage they chose rich-oxalate black tea. Patients' daily intake of calcium was low and didn't exceed 520 mg. Vitamin C consumption was higher than Polish Dietary Reference Intake (DRI) and vitamin B6 lower than DRI. In the management of stone patients, to lower the risk of recurrence, appropriate diet (according to the type of stone) should be provided by dietitian.