Zinc and copper levels in premenstrual syndrome

To determine whether changes in peripheral zinc and copper levels are associated with symptoms of premenstrual syndrome (PMS). Ten PMS patients and 10 controls gave blood at 2- or 3-day intervals through three menstrual cycles. Serum zinc and copper were measured by flameless atomic absorption spectrophotometry. In the controls, zinc values were not significantly different between the follicular and the luteal phases. In the patients, the values were significantly lower during the luteal phase than during the follicular phase. Lower levels of zinc during the luteal phase in PMS patients, compared with the controls, were noted. Copper levels were noted to be higher during the luteal phase in PMS patients compared with the controls. Because copper competes with zinc for intestinal absorption and serum protein binding sites, zinc:copper ratio can reflect the availability of zinc in the body. The computation of this ratio revealed that the ratio was significantly lower in the patients than those in the controls during the luteal phase. Our data suggest that zinc deficiency occurs in PMS patients during the luteal phase, and the availability of zinc in PMS patients during the luteal phase is further reduced by the elevated copper.