Excess calcium increases bone zinc concentration without affecting zinc absorption in rats

Abstract

We examined zinc (Zn) metabolism in rats given diets containing excess calcium (Ca). Rats were given phytate-free diet containing 5 g Ca/kg (control), 12.5 g Ca/kg, or 25 g Ca/kg for 4 wk in Experiment 1. The dietary treatment did not affect Zn concentration in the plasma, testis, kidney, spleen and liver; however, Zn concentration in the femur and its cortex was significantly higher in rats given diet containing 25 g Ca/kg than in other rats. Rats were given phytate-free diet containing 5 g Ca /kg or 25 g Ca /kg for 4 wk in Experiment 2. After 12-h food deprivation, rats were given a diet extrinsically labeled by 67Zn with dysprosium as a fecal marker for 4 h. Feces were collected from 1 d before administration of the labeled diet to 5 d after administration. Excess Ca did not affect the true absorption of Zn and its endogenous excretion but increased femoral Zn. These results suggest that excess Ca improves Zn bioavailability without affecting Zn absorption when diets do not contain phytate.

Effect of calcium-supplemented goat or cow milk on zinc status in rats with nutritional ferropenic anaemia

“…The effect of excess Ca on Zn absorption remains controversial: our results are in disagreement with those reported in other studies that showed that an excess Ca diet either did not affect (Takasugi et al, 2007) or decreased (Dursun & Aydogan, 1994;Wood & Zheng, 1997) the absorption of Zn. However, in our study, the supplementation of Ca in the diet increased the nutritive utilization of Zn in both in the control and the anaemic rats for the goat milk diet and in the control rats for the cow milk diet.…”

“…Dursun and Aydogan (1994) showed that a diet containing 20 g Ca kg À1 decreased the true absorption of Zn in rats. Takasugi et al, (2007) showed that excess Ca of 25 g kg À1 diet, did not affect the true absorption of Zn and its endogenous excretion.…”

Magnesium Supplementation did not Affect the Increasing Bone Zinc Concentration in Rats Given Excess Calcium as Carbonate

“…The reduction of Mg absorption was unlikely to be enough for lowering plasma Mg concentration in the HC group in the present experiment. Femoral Zn concentration increased in the HC rats, which was supported by other reports indicating that excess Ca as carbonate increased the Zn concentration in bone [5,6,7]. Planells et al [8] reported that Mg deficiency increased bone Zn concentration in rats.…”

“…Although excess Ca as carbonate decreases bone Zn concentration in animals given high phytate diets through suppressing Zn absorption [4], Takasugi et al [5] indicated that excess Ca as carbonate increased bone Zn concentration without affecting true absorption of Zn in rats given a phytate-free diet. Furthermore, some other reports also showed that excess Ca as carbonate increased bone Zn concentration and decreased renal Zn concentration in rats given a phytate-free diet [6,7].…”

Response of lactic acid bacteria to milk fortification with dietary zinc salts

“…These foods are also characterized by high phosphorous and calcium contents (Simova, Ivanov, & Simov, 2008). To date, the effect of calcium on zinc absorption has been intensely debated: some authors have suggested that it decreases zinc bioavailability (Dursun & Aydogan, 1994;Hunt, 2003;Maret & Sandstead, 2006;Walter, Rimbach, Most, & Pallauf, 2000), while others state that it has no influence (Hallberg, Brune, Erlandsson, Sandberg, & Rossander-Hultén, 1991;Lönnerdal, 2000;Takasugi, Matsui, Omori, & Yano, 2007) or even a stimulatory effect (Diaz-Castro, Alferez, Lopez-Aliaga, Nestares, & Campos, 2009). A further property that makes milk-based products like yoghurt and cheese the logical choice for zinc fortification is their low pH (Rosado, 2003).…”