Mohamedshah F Y, Moser-Veillon P B, Yamini S, Douglass L W, Anderson R A, Veillon C
Department of Nutrition and Food Science, University of Maryland at College Park, 20742, USA.
Am J Clin Nutr. 1998 Jun;67(6):1250-5. doi: 10.1093/ajcn/67.6.1250.
To determine the fate and distribution of chromium during lactation, six lactating women (25-38 y old) were given three doses of the tracer 53Cr (7.55 micromol/d, or 400 microg/d) on days 1, 2, and 3 of the study. Diet records, blood samples taken while subjects were fasting, and 24-h composite milk and urine samples were collected from day 0 to day 6. Fasting blood samples, morning milk samples, and 24-h urine samples were also collected on days 8, 10, 15, 30, 60, and 90. 53Cr and natural and total chromium concentrations in biological fluids were measured with gas chromatography-mass spectrometry and total urinary chromium was measured with atomic-absorption spectrometry. 53Cr was detectable in serum 2 h after dosing and continued to be detected from day 30 to day 60. Changes in total serum chromium concentration in response to the oral dose suggested that chromium concentrations in blood were not tightly regulated. 53Cr was not detected in breast milk and no significant changes in natural chromium concentration in milk were observed in response to the oral doses, suggesting that breast-milk chromium concentrations are independent of intake. The estimated chromium intake of exclusively breast-fed infants was 2.5 nmol/d (0.13 microg/d), below the lower end of the range of estimated safe and adequate daily dietary intakes (10-40 microg/d) for infants 0-6 mo of age. The baseline chromium concentration in urine and the minimum 53Cr absorption in lactating women were comparable with values for nonpregnant, nonlactating subjects. Chromium losses in breast milk do not appear to be compensated for via increased absorption or decreased excretion.
为了确定哺乳期铬的去向和分布，在研究的第1、2和3天，给6名哺乳期妇女（25 - 38岁）服用了三剂示踪剂53Cr（7.55微摩尔/天，或400微克/天）。从第0天到第6天收集饮食记录、受试者空腹时采集的血样以及24小时混合奶样和尿样。在第8、10、15、30、60和90天还收集了空腹血样、晨奶样和24小时尿样。用气相色谱 - 质谱法测量生物体液中的53Cr以及天然铬和总铬浓度，用原子吸收光谱法测量尿中总铬。给药后2小时血清中可检测到53Cr，并且从第30天到第60天持续被检测到。口服剂量后血清总铬浓度的变化表明血液中的铬浓度没有受到严格调控。母乳中未检测到53Cr，并且口服剂量后母乳中天然铬浓度未观察到显著变化，这表明母乳中的铬浓度与摄入量无关。纯母乳喂养婴儿的估计铬摄入量为2.5纳摩尔/天（0.13微克/天），低于0 - 6月龄婴儿估计安全和充足每日膳食摄入量范围（10 - 40微克/天）的下限。哺乳期妇女尿中的基线铬浓度和53Cr的最低吸收率与非孕、非哺乳期受试者的值相当。母乳中的铬损失似乎无法通过增加吸收或减少排泄来补偿。
