Abstract
Enteral formulas fortified with trace elements, i.e., Mn, Cr, I and Mo besides 4 trace elements, i.e., Fe, Cu, Zn and Se are now commercially available in Japan. We investigated the effects of feeding an enteral formula fortified with 8 trace elements on the blood and tissue concentrations of essential trace element in rats. Five-week-old male rats were divided into 2 groups and fed either a lyophilized commercial enteral formula fortified with 4 trace elements, i.e., Fe, Cu, Zn and Se (MEIBALANCE®-Zcs, 4TE) or the one fortified with Mn, Cr, I, and Mo additionally to 4TE (MEIBALANCE®, 8TE) for 4 weeks. 4TE and 8TE were equivalent in nutritional composition except for the amount of Cu, Mn, Cr, I and Mo. At the end of the experimental period, we measured 8 trace element concentrations of serum, whole blood and liver with ICP-MS. Iron, Cu, Zn and Se concentrations of serum, whole blood and liver in 8TE group were similar or higher, compared with those in 4TE group. Manganese concentrations of serum and liver were higher in 8TE group than in 4TE group. Iodine concentrations of whole blood and liver were higher in 8TE group than in 4TE group. Molybdenum and Cr concentrations of serum, whole blood and liver in 8TE group were similar to those in 4TE group. 1000 kcal of 8TE contains I, Cr and Mo at the level of Recommended Dietary Allowance and Mn at a half level of Adequate Intake of Dietary Reference Intakes for Japanese, 2005. These observations suggested that while the fortification with Mn and I resulted in increases in body content of Mn and I, the above quantities of Mn, Cr, I and Mo did not deteriorate the availability of the other 4 trace elements.
