Adverse effect after cessation of rats' unjustified iron or iron and zinc supplementation on hematological parameters but not ferritin concentration

Abstract

Background & aims: Studies on the impact of supplementation cessation are lacking. We investigated the effect of iron and iron/zinc supplementation and cessation of this intervention on iron status parameters.

Methods: The study was conducted on 6-week male Wistar rats, in 3 stages: 4-week adaptation to the diets: C--control (AIN-93M) and D--iron deficient (mineral mix without iron); 4-week supplementation: 10-times more iron (CSFe, DSFe) or iron/zinc (CSFeZn, DSFeZn) compared to C; 2-week post-supplementation period (the same diets as in the first stage). Red blood cell count, hemoglobin, hematocrit, transferrin saturation (TSAT) and ferritin concentration were determined.

Results: After stage II D rats had statistically significantly (p-value ≤ 0.05) lower hemoglobin and TSAT in comparison to DSFe rats, but not DSFeZn, and significantly lower ferritin concentration in comparison to DSFe and DSFeZn rats. After stage III, CSFe and CSFeZn rats had a significantly lower level of all analyzed hematology parameters compared to C, in contrast rats fed DSFe and DSFeZn diets had higher hemoglobin concentration and hematocrit in comparison to D group. Moreover, in comparison to D rats those fed DSFe diet had higher TSAT and those fed DSFe and DSFeZn diets had significantly higher ferritin concentration.

Conclusions: After cessation of unjustified both iron and iron/zinc supplementation resulted in an adverse effect on hematological but not other iron status parameters. In the situation of iron deficiency in the diet, iron supplementation alone had a prolonged beneficial effect and was more effective than simultaneous iron/zinc supplementation in the improvement of the iron status.

Keywords: Hematological parameters; Iron; Rats; Supplementation; Zinc.