Klemm Rolf D W, West Keith P, Palmer Amanda C, Johnson Quentin, Randall Philip, Ranum Peter, Northrop-Clewes Christine
Center for Human Nutrition, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., W2505, Baltimore, MD 21205, USA.
Food Nutr Bull. 2010 Mar;31(1 Suppl):S47-61. doi: 10.1177/15648265100311S105.
Vitamin A deficiency is a major public health nutrition problem, affecting an estimated 190 million preschool-aged children and 19 million pregnant and lactating women globally, and 83 million adolescents in Southeast Asia alone. Its consequences (disorders) include xerophthalmia (the leading cause of early childhood blindness), increased severity of infection, anemia, and death. Because vitamin A deficiency is largely due to chronic dietary insufficiency of preformed vitamin A and proactive carotenoids, food fortification can offer an effective approach to prevention.
To provide guidance on fortifying wheat and maize flour milled in industrial rollers for national fortification programs in countries where vitamin A deficiency is considered a public health problem.
Critical review of the literature on the dietary gap in vitamin A intake and levels of wheat flour intake among risk groups as a basis for determining vitamin A fortificant levels. Additional review of efficacy evidence, safety and cost considerations, and country experiences related to wheat-flour fortification with vitamin A.
Mill-rolled wheat flour is a technically fortifiable, centrally processed food vehicle that, where routinely and adequately consumed by target groups, should be considered a candidate for fortification. Vitamin A can be stable in flour under typical, ambient conditions, with processing losses estimated at approximately 30%, depending on source and premix conditions.
Factors to guide a decision to fortify flour with vitamin A include the extent of deficiency, availability of other food vehicle options, the centrality of milling, market reach and population intake distributions of the flour products, the dietary vitamin A intake required, and associated costs. Large gaps persist in knowledge of these factors, which are needed to enable evidence-based fortification in most countries, leaving most decisions to fortify guided by assumptions. Where flour can and should be fortified, guidelines are given for providing nearly 25% of the Recommended Dietary Allowance for vitamin A to vulnerable groups consuming varying ranges of flour products. The costs will vary according to the level of fortification.
维生素A缺乏是一个主要的公共卫生营养问题，全球估计有1.9亿学龄前儿童、1900万孕妇和哺乳期妇女受其影响，仅东南亚就有8300万青少年受影响。其后果（病症）包括干眼症（幼儿失明的主要原因）、感染严重程度增加、贫血和死亡。由于维生素A缺乏主要是由于预先形成的维生素A和活性类胡萝卜素的长期膳食不足，食品强化是一种有效的预防方法。
为在维生素A缺乏被视为公共卫生问题的国家，为国家强化计划中工业滚筒磨制的小麦和玉米粉强化提供指导。
对有关维生素A摄入量的膳食差距以及风险群体中面粉摄入量水平的文献进行批判性综述，以此作为确定维生素A强化剂水平的基础。另外还综述了维生素A强化小麦粉的功效证据、安全性和成本考量以及国家经验。
工业滚筒磨制的小麦粉是一种在技术上可强化的、集中加工的食品载体，如果目标群体经常且适量食用，应被视为强化的候选对象。在典型的环境条件下，维生素A在面粉中可以保持稳定，加工损失估计约为30%，具体取决于来源和预混条件。
指导面粉强化维生素A决策的因素包括缺乏程度、其他食品载体选项的可用性、磨粉的核心地位、面粉产品的市场覆盖范围和人群摄入量分布、所需的膳食维生素A摄入量以及相关成本。在这些因素方面仍存在很大差距，而大多数国家进行循证强化需要了解这些因素，这使得大多数强化决策是基于假设做出的。在面粉能够且应该强化的地方，给出了为食用不同范围面粉产品的弱势群体提供近25%维生素A推荐膳食摄入量的指导原则。成本将因强化水平而异。
