The protective effect of endogenous sex hormones is commonly believed to explain the gender gap in the risk of coronary heart disease and the diminished protection in women when menopause occurs. Recent reports indicate that iron overload, due to cessation of menstrual bleeding, may be an important factor. We therefore investigated iron stores by serum ferritin measurements in healthy premenopausal (n=113) and postmenopausal (n=46) women. Ferritin levels were higher in postmenopausal than in premenopausal women, both in blood donors (43.4 versus 23.1 mu g/L, P<.001) and in nondonors (71.7 versus 32.8 mu g/L, P<.001). Serum ferritin was positively correlated with age (r=.36, P<.001). After age adjustment, serum ferritin was positively correlated with hemoglobin, hematocrit, serum total cholesterol, and low-density lipoprotein (LDL) cholesterol. Total cholesterol was correlated with age (r=.66, P<.001), as were LDL cholesterol (r=.60, P<.01) and high-density lipoprotein cholesterol (r=.32, P<.01). Neither ferritin nor serum lipids were directly associated with female sex hormone levels. The mutual relation between ferritin, hemoglobin, and hematocrit probably only indicates their usefulness as measures of body iron. The parallel rise in serum ferritin, total cholesterol, and LDL cholesterol might contribute to the increased risk of coronary heart disease among postmenopausal women.