Nutritional and trace element status as measured by plasma concentrations of magnesium, zinc, retinol (vitamin A), and alpha-tocopherol (vitamin E) and the activities of red cell enzymes dependent on thiamin and pyridoxine (vitamin B-6) were determined in 38 women suffering premenstrual syndrome and in 23 control subjects. Blood samples were collected in the premenstrual and in midfollicular phase. Diagnosis of premenstrual syndrome was based on accepted retrospective criteria and on prospective symptom reports collected over three menstrual cycles. No evidence was found to support the hypothesis that premenstrual symptoms are caused by absolute or relative nutritional deficiencies.