Effects of trace elements of Zn,Fe intake on susceptibility of infectious diseases in children

Objective To examine the effects of children's nutrition condition of zinc (Zn) and iron(Fe) on status of immunization indicators.Methods A total of 1 023 students of 1-6 grades were investigated about their general state of health,5 days diet and 1 month food frequency,recurrent respiratory tract infection (RRTI) status and 262 children's immune indicators were determined after informing the consent to their parents.Results The average intakes of Zn,Fe were 60%-80% of the recommended nutrient intake (RNI) and the rates of adequate intake(AI) were 20%-30%.The intake of Fe was adequate,but only 9.9% of the Fe was from heme-iron.The results of immunization indicators detects showed that the percentages of CD3⁺ cells,the ratio of CD4⁺/CD8⁺,IgA,and IgM were all below the reference value among the students.The incidence of RRTI was 12.6 %.The CD4⁺,CD4⁺/CD8⁺,IgA and IgM were at the normal level for the students with the Zn intake level of ≥80% OF RNI or the Fe intake level of ≥200% OF AI.Conclusion The intakes of Zn and hme-iron were lower for the most of the students.The studetns immune levels are normal when their Zn intake ≥80% of RNI or their Fe intake ≥200% of AI.