Fluoride metabolism in patients with chronic renal failure

Studies of fluoride metabolism were carried out in patients with chronic renal failure by determining fluoride balances for several weeks. The fluoride intake was due to the analyzed fluoride content of the diet and of the drinking water. The effect of aluminum hydroxide on fluoride metabolism was investigated because this antacid is commonly used therapeutically for these patients. Studies have shown that urinary fluoride excretion in patients with chronic renal failure was significantly lower than that in patients with normal renal function, resulting in a signicantly higher retention of fluoride. Although the fecal fluoride excretion in patients with chronic renal failure was slightly but significantly increased, this change did not compensate for the decrease of the urinary fluoride excretion. The intake of aluminum hydroxide resulted in a significant increase of fecal fluoride excretion and in a significant decrease of net absorption and retention of fluoride in patients with chronic renal failure.