Zinc supplementation does not alter plasma trace elements in Kenyan adults

Abstract

Multiple micronutrient deficiencies constitute a significant public health problem in Kenya. Low iron (Fe) and zinc (Zn) status are frequent. As micronutrient homeostasis may be compromised when single‐micronutrients are used in intervention studies, we examined the effects of dietary Zn supplementation on other plasma trace elements (Ca, Cu, Fe, K, Mg, Mn and Se) in free‐living adults participating in an anti‐diarrheal study.MethodsA double‐blind, RCT involving 500 adults, aged 18‐55 years, were supplemented with either 20 mg elemental Zn (as Zn‐sulphate) or placebo, per day for 90 days. Plasma trace elements were analyzed by ICP‐OES. Indices of inflammation (serum ferritin, C‐Reactive Protein) and vitamin A (VA) were also analyzed, using standard kits.ResultsAt baseline, 99% of subjects had elevated plasma Mn (>0.15 µg/dL), 33% were Zn‐deficient (<65 µg/dL), 32% were VA‐deficient (<30 µg/dl), and 14% were Fe‐deficient (<60 µg/dL). After 90 days of supplementation, concentrations of plasma Zn increased 18.5% (p<0.0001) in subjects receiving Zn‐supplements, while it was not different in the placebo group (p=0.30). Zn‐supplementation did not modify Ca, Cu, Fe, K, Mg, Mn, Se, ferritin or CRP values.ConclusionZn supplementation at moderate doses does not lead to deleterious effects on plasma trace elements, or indices of inflammation, in adults in western Kenya.The study was funded by the U.S. Army MRMC