Rioux France M, LeBlanc Caroline P
Ecole des sciences des aliments, de nutrition et d'Etudes familiales, Université de Moncton, 65 Massey Ave, Moncton, NB E1A 3E9, Canada.
Appl Physiol Nutr Metab. 2007 Apr;32(2):282-8. doi: 10.1139/H07-012.
Iron-deficiency anemia is still prevalent among pregnant women living in industrialized countries such as Canada. To prevent this deficiency, iron supplements (30 mg/d) are routinely prescribed to Canadian pregnant women. Recently, dietary reference intakes for iron have increased from 18 and 23 mg/d during the second and third trimesters, respectively, to 27 mg/d throughout the pregnancy for all age groups. Whether this new recommendation implies an increase of iron dosage in supplements has not been answered. Are there any benefits or risks for the mother and her infant associated with iron supplementation during pregnancy? If iron supplementation is recommended, what should be the ideal dosage? This article reviews current knowledge on the potential negative or positive impact of iron supplementation during pregnancy on the outcomes of both infants and mothers. Based on the literature reviewed, a low daily dose of iron (30 mg elemental iron) during pregnancy improves women's iron status and seems to protect their infants from iron-deficiency anemia. Several studies have also shown that a low daily dose of iron may improve birth weight even in non-anemic pregnant women. However, higher dosages are not recommended because of the potential negative effects on mineral absorption, oxidative pathways, and adverse gastrointestinal symptoms. To date, it is still not clear if health professionals should recommend routine or selective supplementation. However, neither routine nor selective iron supplementation during pregnancy is able to eliminate iron-deficiency anemia. Even though the dietary reference intake for iron during pregnancy has been recently increased, we do not recommend higher doses of iron in supplements designed for pregnant women.
缺铁性贫血在加拿大等工业化国家的孕妇中仍然普遍存在。为预防这种缺铁情况，加拿大孕妇通常会被开具铁补充剂（30毫克/天）。最近，铁的膳食参考摄入量已从妊娠中期和晚期分别为18毫克/天和23毫克/天，提高到所有年龄组在整个孕期均为27毫克/天。这一新建议是否意味着补充剂中铁剂量的增加尚未有定论。孕期补充铁剂对母亲及其婴儿是否有任何益处或风险？如果建议补充铁剂，理想剂量应该是多少？本文综述了关于孕期补充铁剂对母婴结局潜在负面影响或正面影响的现有知识。基于所综述的文献，孕期每日低剂量铁（30毫克元素铁）可改善女性的铁状态，并似乎能保护其婴儿免于缺铁性贫血。多项研究还表明，即使对于非贫血孕妇，每日低剂量铁也可能改善出生体重。然而，由于对矿物质吸收、氧化途径以及不良胃肠道症状可能产生负面影响，不建议使用更高剂量。迄今为止，卫生专业人员是否应建议常规或选择性补充铁剂仍不明确。然而，孕期常规或选择性补充铁剂均无法消除缺铁性贫血。尽管最近孕期铁的膳食参考摄入量有所提高，但我们不建议为孕妇设计的补充剂中使用更高剂量的铁。
