Manganese absorption and retention by young women is associated with serum ferritin concentration

Abstract

The interaction between iron and manganese in the gut is well characterized but iron status has not been shown to affect manganese absorption. The objective of this study was to determine whether iron status as determined by serum ferritin concentrations affects manganese absorption, retention, balance, and status. 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. 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. 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.