Zinc deficiency in Mexican American children: influence of zinc and other micronutrients on T cells, cytokines, and antiinflammatory plasma proteins.

BACKGROUND

The Third National Health and Nutrition Examination Survey suggested some Mexican American children are at risk of zinc deficiency.

OBJECTIVE

We measured the effects of zinc and micronutrients or of micronutrients alone on indexes of cell-mediated immunity and antiinflammatory plasma proteins.

DESIGN

Subjects (n = 54) aged 6-7 y were randomly assigned and treated in double-blind fashion in equal numbers with 20 mg Zn (as sulfate) and micronutrients or with micronutrients alone 5 d/wk for 10 wk.

RESULTS

Before treatment the mean +/- SD plasma zinc was 14.9 +/- 1.7 micromol/dL and the range was within the reference; hair zinc was 1.78 +/- 0.52 micromol/g and 41.6% were < or =1.68 micromol/g; serum ferritin was 25.7 +/- 18.6 microg/L and 50.0% were < or =20 microg/L. The zinc and micronutrients treatment increased the lymphocyte ratios of CD4(+) to CD8(+) and of CD4(+)CD45RA(+) to CD4(+)CD45RO(+), increased the ex vivo generation of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), decreased the generation of interleukin-10 (IL-10), and increased plasma interleukin-1 receptor antagonist (sIL-1ra) and soluble tumor necrosis factor receptor 1 (sTNF-R1). Micronutrients alone increased the ratio of CD4(+) to CD8(+) but not of CD4(+)CD45RA(+) to CD4(+)CD45RO(+), increased IFN-gamma but had no effect on IL-2 or IL-10, and increased sIL-1ra but not sTNF-R1. Efficacy of zinc and micronutrients was greater than micronutrients alone for all indexes except the ratio of CD4(+) to CD8(+), which was affected similarly.

CONCLUSIONS

Before treatment, concentrations of hair zinc in 41.6% of subjects and serum ferritin in 50% were consistent with the presence of zinc deficiency. The greater efficacy of the zinc and micronutrients treatment compared with micronutrients alone supports this interpretation.