Iron and zinc nutriture of premenopausal women: associations of diet with serum ferritin and plasma zinc disappearance and of serum ferritin with plasma zinc and plasma zinc disappearance.

The Second National Health and Nutrition Examination Survey found low iron and zinc intakes and low serum ferritin in many premenopausal women. Therefore food frequency history, serum ferritin, plasma zinc, plasma zinc disappearance, and zinc turnover rate were measured in healthy premenopausal women. Plasma zinc disappearance and turnover rate were determined by inductively coupled plasma mass spectroscopic analysis of the plasma ratio of zinc 67 to zinc 68 before and 30 to 60 minutes after intravenous injection of 67Zn. Food frequency predicted serum ferritin concentration in 38 women and plasma zinc disappearance in 19. Frequent red meat intake was associated with higher serum ferritin concentration and a "normal" plasma zinc disappearance. Frequent milk intake was associated with lower serum ferritin concentration and a rapid plasma zinc disappearance. After exclusion of an outlier, in 18 women serum ferritin concentrations were lower when plasma zinc was < 70 micrograms/dl (p < 0.03), and plasma zinc disappearance and turnover rate were higher when serum ferritin was < 20 ng/ml (p < 0.05). Serum ferritin concentration and plasma zinc disappearance constant were inversely and nonlinearly related (R2 = 0.777, p = 0.0003). These findings suggest that avoidance of red meat increases the risk of iron and zinc deficiencies, and low serum ferritin concentrations suggest the possibility of low zinc nutriture.