Boron is a trace mineral naturally occurring in many foods, but it is particularly abundant in peanut butter, wine, raisins and nuts. The U.S. FDA has not established a DV for boron, but growing evidence suggests it is essential to human beings. In the U.S., adult men consume a mean of 1.17 mg/day and women consume 0.96 mg/day. Vegetarian adults consume slightly more 1.
Up to 18 mg/day of boron appears to be safe for adults even if taken for long periods of time. There is no evidence that it is either carcinogenic or mutagenic. No adverse effects have been observed in women taking boron supplements 2.