Twenty-nine college females, aged 18-29, participated in a six month boron supplementation protocol to evaluate mineral and hormone status of athletes and non-athletes. All subjects were classified into activity and oral contraceptive groups as follows: athletes (n=16), non-athletes (n=13), oral contraceptives (n=12), and no oral contraceptives (n=17). Subjects were randomly assigned to receive a placebo or 3 mg of boron per day. Subjects' maximal oxygen consumption (VO₂max) was assessed as a baseline measurement and was used to confirm a difference between activity groups. Body fat, height, bone mineral density, and serum calcitonin and parathyroid also were baseline measurements. Subjects were measured at baseline and six months for the following: dietary intake, body weight, serum levels of 17-f-estradiol, progesterone, and testosterone, and plasma and urine levels of calcium, phosphorus, magnesium, and boron. Athletes had a Significantly greater VO₂max (p < 0.01) than did non-athletes. Subjects taking oral contraceptives had significantly lower serum estradiol (p < 0.05) as compared to subjects not taking oral contraceptives. Boron supplemented non-athletes had a significantly greater change in plasma calcium levels (p < 0.05) as compared to boron supplemented athletes, although the athletes had a significantly higher plasma calcium level (p < 0.05) at the baseline measurement. Control subjects (n=6) had a significantly greater change in dietary carbohydrate (p < 0.01) and protein intake (p < 0.05) as compared to subjects taking boron (n=23). Boron supplementation did not appear to significantly influence any of the parameters measured. However, boron supplementation combined with activity appeared to influence plasma calcium, while serum estradiol may be influenced by oral contraceptives. / Master of Science