Metabolic responses of postmenopausal women to supplemental dietary boron and aluminum during usual and low magnesium intake: Boron, calcium, and magnesium absorption and retention and blood mineral concentrations
Metabolic responses of postmenopausal women to supplemental dietary boron and aluminum during usual and low magnesium intake: Boron, calcium, and magnesium absorption and retention and blood mineral concentrations
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DOI：
10.1093/ajcn/65.3.803
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发表时间：
1997-03-01
影响因子：
7.1
通讯作者：
Nielsen, FH
中科院分区：
文献类型：
--
作者：
Hunt, CD;Herbel, JL;Nielsen, FH
动物研究的结果表明，饮食中的硼影响矿物质代谢的几个方面，特别是当动物受到营养压力的时候。11名绝经后志愿者在代谢病房生活167d(1个23d平衡期和6个24d治疗期)，喂以常规基础饮食，每天平均摄入量为0.36 mg B、109 mg和0.10 mg Al/8400kJ。他们补充0(Be)或3 mg B(SE，仅限最后两个周期)、0(BMG)或200 mg mg(SMG)(后两个周期镁补充剂保持不变)、0(Bal)或1000 mg Al(SAL)/d。与Be处理相比，SE处理使膳食中的硼增加了9.0倍，但对血浆中的硼浓度只增加了1.5倍。不考虑硼的饮食处理，粪便和尿液中的硼排泄量占饮食中硼摄入量的近100%，没有证据表明随着时间的推移，硼会积累。在大幅增加饮食中的硼时，缺乏硼的积累和血液中的硼值变化相对较小，这支持了硼的动态平衡的概念。在喂食BMG的受试者中，SE降低了饮食中钙在尿液中损失的百分比，但在喂食SMG的志愿者中，这一比例增加了这一比例，这一关系可能对理解扰乱钙平衡的代谢矿物质紊乱很重要。SAI期间钙吸收减少提示应限制或至少监测有过度钙丢失倾向的绝经后妇女的铝补充量。BMG受试者SE期间尿草酸总量降低提示硼在低镁营养时控制尿石症中可能起到作用。
Findings from animal studies indicate that dietary boron affects several aspects of mineral metabolism, especially when animals are subjected to nutritional stressors. Eleven postmenopausal volunteers living on a metabolic ward for 167 d (one 23-d equilibration period and six 24-d treatment periods) were fed a conventional basal diet that supplied a daily average intake of 0.36 mg B, 109 mg Mg, and < 0.10 mg Al/8400 kJ. They were given supplements of 0 (BE) or 3 mg B (SE, last two periods only), 0 (BMg) or 200 mg Mg (SMg) (with magnesium supplements held constant during the last two periods), or 0 (BAl) or 1000 mg Al (SAl)/d. The SE treatment, compared with the BE treatment, provided a 9.0-fold increase in dietary boron but yielded only a 1.5-fold increase in plasma boron concentrations. Regardless of boron dietary treatment, fecal plus urinary excretion of boron accounted for nearly 100% of dietary boron intake with no evidence of boron accumulation over time. Lack of boron accumulation and relatively small changes in blood boron values during a substantial increase in dietary boron support the concept of boron homeostasis. In subjects fed BMg, SE decreased the percentage of dietary calcium lost in the urine but increased that percentage in volunteers fed SMg, a relation that may be important in understanding metabolic mineral disorders that perturb calcium balance. Reduced calcium absorption during SAI suggests that aluminum supplementation should be limited or at least monitored in postmenopausal women prone to excessive calcium loss. Decreased total urinary oxalate during SE in BMg subjects indicates a possible role for boron in the control of urolithiasis during low-magnesium nutriture.