塩化カリウムまたはクエン酸カリウムの多量摂取がラットの成長と亜鉛利用性に及ぼす影響

抄録

Various supplements containing potassium citrate (KCit) and potassium chloride (KCl) are currently available and the overdose of these supplements is expected to cause health problems. Because KCit but not KCl is known as an alkalinizing salt, the effects of high intake may be different between KCit and KCl. Some studies have suggested that dietary citrate affects zinc metabolism, in which the action of citrate is not consistent. In this study, growing rats were given a feed supplemented with KCit or KCl, as dietary potassium (K) content was five-fold more than its requirement, for four weeks. The growth and the femoral zinc concentration were examined. Both K salts did not affect plasma K concentration and feed intake, but reduced feed efficiency and weight gain. Further, feed efficiency and weight gain were not different between the KCit and the KCl groups. Neither K salt affected the relative weight to body weight in the liver, the kidney, the spleen, and the femur. These results suggested that the high intake of both K salts at the level of this study did not disturb K homeostasis but suppressed growth through lowering feed efficiency. Additionally, bone zinc concentration decreased in the KCit group as well as the KCl group, suggesting that K overdose disturbed zinc metabolism, irrespective of its form. Further research is necessary for clarifying the effect of high intake of citric acid and K on zinc metabolism in detail.