Geissler P W, Shulman C E, Prince R J, Mutemi W, Mnazi C, Friis H, Lowe B
Danish Bilharziasis Laboratory, Charlottenlund, Denmark.
Trans R Soc Trop Med Hyg. 1998 Sep-Oct;92(5):549-53. doi: 10.1016/s0035-9203(98)90910-5.
In a cross sectional survey based in an antenatal clinic at Kilifi District Hospital, Coast Province, Kenya, 154 of 275 pregnant women (56%) reported eating soil regularly. Geophagous women had lower haemoglobin and serum ferritin concentrations than non-geophagous women (mean haemoglobin level 9.1 vs. 10.0 g/dL, P < 0.001; median ferritin level 4.5 vs. 9.0 micrograms/L, P < 0.001). In multiple linear regression analyses, geophagy was a significant predictor of haemoglobin (beta = -6.4, P = 0.01) and serum ferritin concentrations (beta = -6.6, P = 0.002), while controlling for gestational age and malaria and hookworm infection. Another 38 pregnant women, who reported eating soil regularly, participated in focus group discussions and were interviewed on geophagy. The most commonly eaten soil was from the walls of houses. The median estimated daily intake was 41.5 g (range 2.5-219.0 g). Twenty-seven of these women assisted in the collection of soil samples which were then analysed for their content of iron, zinc and aluminium after extraction with 0.1 M HC1. The average daily soil intake supplied the geophagous women with 4.3 mg of iron, corresponding to 14% of the recommended dietary allowance of iron for pregnant women. The study revealed a strong negative association between geophagy and both haemoglobin and ferritin status. At the same time it demonstrated the potential of soil as a source of dietary iron for geophagous women. These seemingly contradictory results might be due to other components in the soil interfering with iron uptake or metabolism. Alternatively, it may be that the geophagous women had extremely depleted iron stores before starting to eat soil. From these cross-sectional data, no inference about causality could be made.
在肯尼亚海岸省基利菲区医院产前诊所进行的一项横断面调查中，275名孕妇中有154名（56%）报告经常吃土。吃土的孕妇血红蛋白和血清铁蛋白浓度低于不吃土的孕妇（平均血红蛋白水平9.1 vs. 10.0 g/dL，P < 0.001；铁蛋白水平中位数4.5 vs. 9.0微克/升，P < 0.001）。在多元线性回归分析中，吃土是血红蛋白（β = -6.4，P = 0.01）和血清铁蛋白浓度（β = -6.6，P = 0.002）的显著预测因素，同时控制了孕周、疟疾和钩虫感染。另外38名经常吃土的孕妇参加了焦点小组讨论，并接受了关于吃土的访谈。最常吃的土来自房屋墙壁。估计每日摄入量中位数为41.5克（范围2.5 - 219.0克）。其中27名女性协助采集了土壤样本，然后用0.1 M盐酸提取后分析其铁、锌和铝含量。吃土女性的平均每日土壤摄入量为她们提供了4.3毫克铁，相当于孕妇铁推荐膳食摄入量的14%。该研究揭示了吃土与血红蛋白和铁蛋白状态之间存在强烈的负相关。同时，它证明了土壤作为吃土女性膳食铁来源的潜力。这些看似矛盾的结果可能是由于土壤中的其他成分干扰了铁的吸收或代谢。或者，可能是吃土的女性在开始吃土之前铁储备就极度匮乏。从这些横断面数据中，无法得出因果关系的推断。
