Dietary fibre: the effectiveness of a high bran intake in reducing renal calcium excretion.

Fifteen healthy women were given a standardized calcium-rich diet (1800 mg calcium/day) with or without 36 g bran for 5 days. A similar study was also carried out with rice, soy and wheat bran. Urine samples were also collected 24 h. With all brans renal calcium excretion decreased and renal oxalic acid excretion increased. However, influence of rice bran was statistically significant. After 5 days of consuming 36 g rice bran/day 14 of 15 subjects showed decreased calcium excretion, but increased oxalic acid excretion. Relative supersaturation with calcium oxalate, as a measure for the risk of calcium stone formation, increased after addition of all brans.