Background: The interaction between iron and manganese in the gut is well characterized but iron status has not been shown to affect manganese absorption.
Objective: The objective of this study was to determine whether iron status as determined by serum ferritin concentrations affects manganese absorption, retention, balance, and status.
Design: The subjects were healthy young women; 11 had serum ferritin concentrations >50 microg/L and 15 had serum ferritin concentrations <15 microg/L. In a crossover design, subjects consumed diets that supplied either 0.7 or 9.5 mg Mn/d for 60 d. Manganese absorption and retention were assessed during the last 30 d of each dietary period by using an oral dose of 54Mn; balance was assessed simultaneously.
Results: Dietary manganese did not affect manganese status, but high serum ferritin depressed arginase activity. The interaction of ferritin status and dietary manganese affected 54Mn absorption and biological half-life. Absorption was greatest in subjects with low ferritin concentrations when they were consuming the low-manganese diet, and was least in subjects with high ferritin concentrations. Biological half-life was longest when subjects with high ferritin concentrations consumed the low-manganese diet, and was shortest in all subjects consuming the high-manganese diet. Manganese balance was only affected by the amount of manganese in the diet.
Conclusions: These results show that iron status, as measured by serum ferritin concentration, is strongly associated with the amount of manganese absorbed from a meal by young women. When greater amounts of manganese are absorbed, the body may compensate by excreting manganese more quickly.