Knudsen E, Sandström B, Solgaard P
Research Department of Human Nutrition, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
J Trace Elem Med Biol. 1996 Jun;10(2):68-76. doi: 10.1016/S0946-672X(96)80014-9.
Zinc, copper and magnesium absorption and retention from a high-fibre and high-phytate diet of conventional foods were investigated in 8 healthy subjects. Fractional absorption of the three minerals was estimated from fecal monitoring of zinc, copper and magnesium stable isotopes added to one day's diet. In addition, apparent absorption, retention and endogenous losses were estimated for the respective minerals based on fecal and urinary excretion over the last 16 days of 21 days constant intake. The diet contained 1 mmol phytic acid, 29 g dietary fiber, 140 mumol zinc, 13 mumol copper, and 9 mmol magnesium per 10 MJ. The absorption of zinc, copper and magnesium was 29 +/- 12% (x +/- SD) (48 +/- 20 mumol), 44 +/- 7% (8 +/- 1 mumol) and 46 +/- 6% (5 +/- 1 mmol), respectively. The retained amounts of minerals were -7 +/- 19 mumol, -5 +/- 4 mumol, and -3 +/- 1 mmol, respectively and the estimated endogenous intestinal losses were 40 +/- 20 mumol, 12 +/- 4 mumol and 3 +/- 1 mmol, respectively. In conclusion, the fractional absorption of zinc, copper and magnesium from the fibre-rich diet was not sufficient to cover intestinal and urinary losses of these elements, resulting in negative balances.
在8名健康受试者中，研究了常规食物组成的高纤维和高植酸饮食中锌、铜和镁的吸收与潴留情况。通过对添加到一日饮食中的锌、铜和镁稳定同位素进行粪便监测，估算这三种矿物质的部分吸收情况。此外，根据21天持续摄入最后16天的粪便和尿液排泄情况，估算了各矿物质的表观吸收、潴留和内源性损失。该饮食每10兆焦耳含有1毫摩尔植酸、29克膳食纤维、140微摩尔锌、13微摩尔铜和9毫摩尔镁。锌、铜和镁的吸收分别为29±12%（x±标准差）（48±20微摩尔）、44±7%（8±1微摩尔）和46±6%（5±1毫摩尔）。矿物质的潴留量分别为-7±19微摩尔、-5±4微摩尔和-3±1毫摩尔，估计的肠道内源性损失分别为40±20微摩尔、12±4微摩尔和3±1毫摩尔。总之，富含纤维饮食中锌、铜和镁的部分吸收不足以弥补这些元素的肠道和尿液损失，导致负平衡。
