Wistar rats were fed a basal stabilized-rice bran diet (B), and five additional ones, fortified to supply either 50 or 100% of zinc and calcium requirements, and a combination furnishing 100% of both minerals. Another diet supplemented with the complete mineral mix (MM) was also used. Results show that the low feed efficiency of B was maximized either by supplementation with MM, or by supplementing bran with 50% of the zinc requirement. Attempts to compensate for the low calcium content of bran by supplementation with 50 or 100% of the mineral requirement, did not increase either feed efficiency, growth or liver zinc. These data confirm that only about 11% of zinc contained in bran is nutritionally available and that supplementing with calcium is detrimental, indicating that this by-product is not a recommendable source of minerals.