Swanson C A, King J C
J Nutr. 1982 Apr;112(4):697-707. doi: 10.1093/jn/112.4.697.
Eight pregnant (P) women in their third trimester and 10 nonpregnant (NP) women participated in a 21-day confined metabolic study. The participants were fed semipurified liquid diets providing 20 mg zinc/day. Apparent zinc balance was calculated and parameters of zinc status assessed. Even though an adequate amount of a readily available form of zinc was fed, the P women consistently maintained lower mean serum zinc concentrations than the NP controls (69 micrograms/dl vs. 97 micrograms/dl). Although the dietary zinc intake was constant throughout the study, most subjects' salivary zinc levels varied greatly. In this study, salivary zinc concentrations was not a sensitive indicator of zinc intake. There were no differences in the concentrations of zinc in hair between the P and NP groups; mean values ranged from 180--220 ppm. In both groups, approximately 95% of the measured zinc output was lost in the feces and only 5% excreted in the urine. The P women tended to excrete more zinc in their urine than the NP women (900 micrograms/day vs. 650 micrograms/day), but they excreted less zinc in their feces. The P women demonstrated a greater apparent zinc retention than the NP women (1.9 +/- 0.6 vs. 0.9 +/- 0.5 mg/day). This difference, however, was not statistically significant (P greater than 0.05).
8名孕晚期孕妇（P）和10名非孕妇（NP）参与了一项为期21天的密闭代谢研究。给参与者提供半纯化液体饮食，每天提供20毫克锌。计算表观锌平衡并评估锌状态参数。尽管提供了足量的易于吸收的锌形式，但孕妇的平均血清锌浓度始终低于非孕妇对照组（69微克/分升对97微克/分升）。尽管在整个研究过程中膳食锌摄入量保持恒定，但大多数受试者的唾液锌水平差异很大。在本研究中，唾液锌浓度不是锌摄入量的敏感指标。孕妇组和非孕妇组之间的头发锌浓度没有差异；平均值在180 - 220 ppm之间。在两组中，大约95%的测量锌排出量通过粪便丢失，只有5%通过尿液排出。孕妇的尿锌排出量往往比非孕妇多（900微克/天对650微克/天），但她们的粪便锌排出量较少。孕妇的表观锌潴留量比非孕妇大（1.9±0.6对0.9±0.5毫克/天）。然而，这种差异无统计学意义（P＞0.05）。
