成本-效益分析法在食物铁强化项目中的应用现状

食物铁强化已经被越来越多的国家作为预防和控制铁缺乏和缺铁性贫血的主要策略。本文就各国食物铁强化项目的成本-效益分析报告进行了综述。目前成本-效益分析的运用范围和影响日益加剧,但是成本-效益方法广泛应用于食物铁强化项目尚待进一步的研究。     

Effect of food fortification with iron on childhood anemia: a review study

A systematic review was conducted to identify studies assessing the effect of food fortification with iron on childhood anemia. The MEDLINE, LILACS, and PubMed databases and WHO and PAHO sites were searched with no time limitation, including articles published in Portuguese, English, or Spanish, using the following key words and their combination: food fortification, iron, effectiveness, efficacy, anemia, flour, staple foods, interventions, and children. Of 21 studies reviewed, only one failed to report a positive, favorable effect of iron fortification, indicating the possibility of publication bias. The studies showed important methodological limitations. The two studies with the best methodological scores showed opposite results, highlighting the need for larger trials with better planning to explore this hypothesis.     

Absorption of fortification iron from milk formulas in infants

The bioavailability of iron added to different types of cows' milk formulas was studied using mono-isotopic and double-isotopic methods in 396 infants aged 5-18 mo. All the milk formulas were fortified with ferrous sulfate in concentrations varying between 10 and 19 mg elemental iron/liter. Iron absorption from low-fat milks and full-fat milks varied from 2.9 to 5.1%. A higher range of mean absorption, 5.9 to 11.3%, was observed in the same formulas with the addition of ascorbic acid at concentrations of 100 mg/l or higher (up to 800 mg/l), demonstrating its enhancing effect on iron absorption in fortified milks. The amount of milk fat, the addition of carbohydrates, or acidification did not seem to influence iron absorption.     

食物强化在国民营养素质改善中的作用

1　国民营养与全面小康国民的健康素质与营养状况有密切关系 ,这是众所共知的。尽管已有充分的科学依据表明碘、铁、ω 3脂肪酸、牛磺酸等营养素与认知能力有关 ,但人们仍比较注重营养与体格发育和疾病的关系 ,而比较忽视营养与智力发育和认知能力的关系。一个人的健康和素质应该包括体力与智力两个方面。这是我国全面建设小康社会的一个不可缺少的条件。在讨论国民营养状况的重要性时 ,一个容易被忽视的方面是营养状况与劳动生产率和国民经济发展的关系。陈春明教授等最近的研究表明 ,通过强制性推广应用碘盐后 ,我国小学生的地方性甲状腺…     

食物强化策略对我国居民营养状况的改善作用

营养素缺乏是一个世界性的健康问题,也是一直困扰我国居民营养与健康的一个突出问题。不论是在建国初期,还是改革开放后,缺铁性贫血、维生素A缺乏等都严重威胁着我国居民,尤其是儿童、妇女、老年人等特殊人群的健康。实践证明,改善人群营养素缺乏的主要措施包括:     

Home fortification of complementary foods with micronutrient supplements is well accepted and has positive effects on infant iron status in Ghana

BACKGROUND: Micronutrient deficiencies are common during infancy, and optimal approaches for their prevention need to be identified. OBJECTIVE: The objective was to compare the efficacy and acceptability of Sprinkles (SP), crushable Nutritabs (NT), and fat-based Nutributter (NB; 108 kcal/d), which provide 6, 16, and 19 vitamins and minerals, respectively, when used for home fortification of complementary foods. DESIGN: Ghanaian infants were randomly assigned to receive SP (n = 105), NT (n = 105), or NB (n = 103) daily from 6 to 12 mo of age. We assessed dietary intake, morbidity, and compliance weekly. Hemoglobin and plasma ferritin, TfR, C-reactive protein, and zinc were measured at 6 and 12 mo. We used an exit interview to assess acceptability. A randomly selected control group of infants who received no intervention (NI; n = 96) were assessed at 12 mo. RESULTS: All supplements were well accepted, and the mean percentage of days that supplements were consumed (87%) did not differ between groups. At 12 mo, all 3 intervention groups had significantly higher ferritin and lower TfR concentrations than did the NI control group. Mean (+/- SD) hemoglobin was significantly higher in NT (112 +/- 14 g/L) and NB (114 +/- 14 g/L) but not in SP (110 +/- 14 g/L) infants than in NI infants (106 +/- 14 g/L). The prevalence of iron deficiency anemia was 31% in the NI control group compared with 10% in the intervention groups combined (P < 0.0001). CONCLUSION: All 3 options for home fortification of complementary foods are effective for reducing the prevalence of iron deficiency in such populations.     

Evaluation of meat as a first complementary food for breastfed infants: impact on iron intake

The rationale for promoting the availability of local, affordable, non-fortified food sources of bioavailable iron in developing countries is considered in this review. Intake of iron from the regular consumption of meat from the age of 6 months is evaluated with respect to physiological requirements. Two major randomized controlled trials evaluating meat as a first and regular complementary food are described in this article. These trials are presently in progress in poor communities in Guatemala, Pakistan, Zambia, Democratic Republic of the Congo, and China.     

Iron absorption in breast-fed infants: effects of age,iron status,iron supplements,and complementary foods

BACKGROUND: Iron supplements are often recommended for older breast-fed infants, but little is known about factors affecting iron absorption from human milk or supplements. OBJECTIVE: We investigated the effects of age, iron status, and iron intake on iron absorption in healthy, term, breast-fed infants. DESIGN: Twenty-five infants were randomly assigned to receive either 1) iron supplements (1 mg x kg(-1) x d(-1)) from 4 to 9 mo of age, 2) placebo from 4 to 6 mo and iron supplements from 6 to 9 mo, or 3) placebo from 4 to 9 mo. Infants were exclusively breast-fed to 6 mo and partially breast-fed to 9 mo of age. Iron absorption was assessed by giving (58)Fe with mother's milk at 6 and 9 mo. Blood samples were obtained at 4, 6, and 9 mo, and complementary food intake was recorded at 9 mo. RESULTS: At 6 mo, mean (+/-SD) fractional iron absorption from human milk was relatively low (16.4 +/- 11.4%), with no significant difference between iron-supplemented and unsupplemented infants. At 9 mo, iron absorption from human milk remained low in iron-supplemented infants (16.9 +/- 9.3%) but was higher (P = 0.01) in unsupplemented infants (36.7 +/- 18.9%). Unexpectedly, iron absorption at 9 mo was not correlated with iron status but was significantly correlated with intake of dietary iron, including supplemental iron. CONCLUSIONS: Changes in the regulation of iron absorption between 6 and 9 mo enhance the infant's ability to adapt to a low-iron diet and provide a mechanism by which some, but not all, infants avoid iron deficiency despite low iron intakes in late infancy.     

The effect of iron fortification and de-worming on anaemia and iron status of Vietnamese schoolchildren

Previous data from Vietnam show that anaemia is highly prevalent among schoolchildren, who are considered not to be iron deficient. Trichuris infection doubled the risk of anaemia. The present study aimed to evaluate the hypothesis that de-worming is more effective than iron fortification in an anaemic, infection-prone population. In a trial with a 2 x 2 factorial design, 425 anaemic children aged 6-8 years were randomly assigned to receive either iron-fortified noodles or placebo, and mebendazole or placebo. Outcomes considered were change in haematological indicators of iron status (Hb, serum ferritin (SF), serum transferrin receptor (TfR) and haemoglobinopathies analysis); inflammations (C-reactive protein (CRP)); parasite infection status (hookworm, Trichuris and Ascaris infection); and IgE. ANOVA and logistic regression were used to assess the effects of iron fortification and de-worming on Hb, SF, TfR, body iron and anaemia. Hb improved in all groups after 6 months of intervention. Iron fortification significantly improved Hb, SF and body iron (2.6 g/l, 16.3 microg/l and 1 mg/kg, respectively). Prevalence of elevated IgE was very high at baseline (99%) and significantly reduced to about 75% in all groups after intervention. De-worming unexpectedly showed no effect on Hb, iron status and IgE level. It is concluded that iron fortification slightly improved anaemia and iron status in anaemic schoolchildren in rural Vietnam that were not considered iron deficient. Chronic infection or other unidentified factors may play an important role in the seasonal reduction of anaemia seen in all treatment groups.     

Effect of food fortification on folic acid intake in the United States

BACKGROUND: The addition of folic acid to all enriched cereal-grain foods, mandated by the Food and Drug Administration (FDA), was initiated in January 1998. Although this program was designed such that typical folate intakes would be increased by approximately 100 micro g/d and that the risk of intakes > 1000 micro g/d (the FDA's safe upper limit of daily intake) would be minimal, its actual effect on folate intake has yet to be determined. OBJECTIVE: The objective was to estimate the effect of folic acid fortification on the amount of folate consumed by persons in the United States. DESIGN: Linear regression analysis of data from published studies was used to determine the relation between a chronic folic acid dose and the resulting increase in steady state concentrations of folate in plasma or serum. Using this regression equation and reverse prediction, we quantified the increase in folic acid intake from fortification required to achieve the increase in plasma or serum folate observed in published studies. RESULTS: The increase in circulating folate concentration was linearly related to folic acid intake over the range of 100-1000 micro g/d (r = 0.984, P < 0.0001). Predicted increases in folic acid intake from fortified food ranged from 215 to 240 micro g/d. CONCLUSIONS: Typical intakes of folic acid from fortified foods are more than twice the level originally predicted. The effect of this much higher level of fortification must be carefully assessed, especially before calls for higher levels of fortification are considered.     

The potential of encapsulated iron compounds in food fortification: a review

Iron (Fe) encapsulation has the potential to help overcome several major challenges in Fe fortification of foods. It may decrease unwanted sensory changes in fortified products and reduce interactions of Fe with food components that lower Fe bioavailability. However, the effect of encapsulation per se on Fe bioavailability is a concern. Rat studies comparing encapsulated ferrous sulfate, ferric ammonium citrate, and ferrous fumarate to non-encapsulated compounds indicate that a ratio of capsule:substrate of > or = 60:40 may decrease the relative bioavailability (RBV) of the Fe by approximately 20%. At a ratio of capsule:substrate of < or = 50:50, the RBV of encapsulated ferrous sulfate appears to be similar to ferrous sulfate. Even minor changes in capsule composition may influence Fe bioavailability. Encapsulated ferrous fumarate given with ascorbic acid as a complementary food supplement and encapsulated ferrous sulfate fortified into salt have been shown to be efficacious in anemic children. For salt fortification, further refinements in Fe capsule design are needed to increase resistance to moisture and abrasion, while maintaining bioavailability. Studies evaluating the potential efficacy of encapsulated Fe in staple cereals (wheat and maize flours) are needed. A potential barrier to use of encapsulated forms of Fe in staple food fortification is the relatively low melting point of the capsules, which may cause unwanted sensory changes during food preparation. Research and development efforts to improve the quality of coatings and their resistance to high temperatures are ongoing. Process costs for encapsulation can be high, and unless they can be reduced, may limit applications. Further research is needed to determine which encapsulation technologies are most effective in ensuring iron bioavailability from encapsulated compounds.     

Safety of universal provision of iron through home fortification of complementary foods in malaria-endemic areas

Home fortification of complementary foods with iron and other micronutrients is a low-cost strategy for filling nutrient gaps in the diets of infants and young children, but there has been uncertainty about the safety of universal provision of iron via home fortification in malaria-endemic areas. Based on the current understanding of the potential mechanisms of adverse effects of iron, the risk can probably be minimized by using the lowest possible efficacious dose of iron, preferably delivered in small amounts throughout the day with food, to minimize spikes in plasma nontransferrin-bound iron and large amounts of unabsorbed iron in the gastrointestinal tract. Results from 6 home fortification studies in malaria-endemic areas showed no increased risk of morbidity (including malaria), but these studies were not powered to rule out a modest increase in the risk of severe adverse events. At present, the safest option is to implement home fortification in the context of comprehensive malaria control strategies, as recommended in recent WHO guidelines.     

云南省4个贫困县婴幼儿辅食添加状况分析

目的 了解云南省贫困农村4个县4个民族婴幼儿辅食添加状况.方法 采用随机整群抽样法和典型抽样法相结合,对2 655名3岁以下婴幼儿的喂养情况、体格发育、患病情况进行问卷调查和体检.采用SPSS软件进行t检验、χ2检验率、的两两比较、Logisitic回归分析.结果 开始添加各类辅食婴幼儿的月龄中位数均为12,未添加辅食的月龄中位数分别为谷类6.5,奶类、蛋类、水果类均为10,蔬菜为9.5;4月龄时添加辅食的累积比例由高到低分别为:谷类61.4%、奶类27.8%、蔬菜19.0%、水果13.2%、蛋类8.4%;21～24月龄时分别为:谷类91.6%、水果53.2%、蔬菜62.5%、蛋类47.4%、奶类41.8%;到5月龄时未添加辅食的婴幼儿比例由高到低分别为:蔬菜83.0%、蛋类82.5%、水果79.6%、奶类66.5%、谷类30.9%.结论 辅食添加过早和过晚同时存在,使急性呼吸道感染、反复呼吸道感染、急性腹泻和慢性腹泻危险度增加,添加谷类、奶类、水果类、蔬菜类对牙齿和骨髓发育有保护作用.     

A randomized placebo-controlled trial of iron supplementation in breastfed young infants initiated on complementary feeding: effect on haematological status

To combat iron deficiency manifesting around six months of age, iron-fortified complementary feeding has been recommended. In developing countries, in view of the poor bioavailability of iron from predominantly cereal-based diets and the high cost of fortification, medicinal iron supplementation is an alternative intervention. This double-blind randomized placebo-controlled trial was conducted from April 1999 to March 2000 in the Out-patient Department of a tertiary hospital in New Delhi, India, to evaluate the haematological effects of medicinal iron supplementation to breastfed young infants initiated on complementary feeding. One hundred healthy non-low birth-weight, predominantly breastfed infants aged 4-6 months were randomized into two groups to receive either iron (2 mg/kg/day) (IS group; n=49) or placebo drops (P group; n=51) beginning with the initiation of home-based non-fortified complementary feeding. Haematological parameters and anthropometry of mothers and infants were measured at baseline and repeated for infants after four and eight weeks of recruitment. Seventy-one subjects (35 in the IS group and the 36 in P group) came for the first follow-up, and of these, 43 (19 in the IS group and 24 in the P group) reported for the second visit. The adjusted (for maternal and baseline infant ferritin) serum ferritin levels were significantly higher in the IS group at both the follow-ups (p=0.006). The adjusted (for maternal ferritin and baseline infant ferritin) change in haemoglobin was significantly higher only at the second follow-up (0.7 g/dL; 95% confidence interval [CI] 0.3-1.0 g/dL). The adjusted rise in haemoglobin was higher in initially anaemic infants (at second follow-up by 1 g/dL; 95% CI 0.5-1.6 g/dL). Medicinal iron supplementation, at the time of initiating complementary feeding, to breastfed young infants resulted in an elevation of serum ferritin and haemoglobin. The response was higher in initially anaemic infants. From a programmatic perspective, evidence needs to be generated on the relative merits of selective (anaemic) versus general supplementation and daily versus weekly supplementation.     

健康教育联合辅食营养包预防婴幼儿缺铁性贫血的效果

目的探讨健康教育联合辅食营养包对婴幼儿缺铁性贫血的预防效果。方法选取2015年1-5月在四川省樊枝花市第二人民医院产科出生的新生儿300例为研究对象,随机分为联合组、健康教育组和对照组,每组各100例。联合组给予健康教育以及营养包添加干预,健康教育组给予健康教育干预,对照组给予普通住院分娩新生儿护理。比较3组患儿血清铁水平以及总铁结合力,缺铁性贫血患病率,红细胞(RBC)、血红蛋白(Hb)、红细胞压积(HCT)、平均红细胞体积(MCV)、平均红细胞血红蛋白量(MCH)水平的差异。结果联合组血清铁总量最高,对照组最低,3组比较,差异有统计学意义(P0.05);联合组总铁结合力最低,对照组最高,3组比较,差异有统计学意义(P0.05)。联合组RBC、Hb、HCT、MCV、MCH水平最高,对照组最低,3组比较,差异有统计学意义(P0.05)。3组贫血程度分布比较,差异有统计学意义(P0.05);联合组贫血发生率最低,对照组最高,3组比较,差异有统计学意义(P0.05)。结论健康教育联合辅食营养包添加能够有效预防婴幼儿缺铁性贫血,值得临床推广应用。     

46个农村贫困县婴幼儿辅食添加现状

目的 分析我国西部农村地区3岁以下儿童辅食添加现状，为政府制定相应的政策提供理论依据。方法 采用分层多阶段抽样的方法。进行横断面调查。以辅食添加率、辅食添加时间和辅食添加频率来分析辅食添加状况，用年龄别身高Z值(HAZ)和年龄别体重Z值(WAZ)判断婴幼儿生长发育水平。结果 所调查婴幼儿谷类辅食的添加率88％，植物蛋白添加率最低为44．7％。五大类辅食的添加率都随着婴幼儿年龄的增加而增加，每一个月龄段各类辅食的添加率都以谷类最高，依次为蔬菜，动物蛋白，蛋类和奶类，植物蛋白最低。辅食开始添加较迟，平均时间在6个月以后，鸡蛋、肉类和蔬菜在8个月左右，豆制品最晚，平均为10个月。4～6月龄每天吃鸡蛋和肉类的比例分别只有16．6％和15．4％，12个月龄以后每天能吃到鸡蛋的比例不到60％，肉类则更低不到50％，6个月龄以后五大类辅食添加组生长迟缓和低体重的发病率都低于未添加，12～24月龄段这种差别最大。结论我国西部农村要幼儿辅食添加存在的主要问题是添加时间不合理，品种单一和实际摄入量低。应该多渠道进行营养知识宣传，大力提倡添加鸡蛋，植物蛋白如豆制品以及蔬菜等，农村地区容易获取的营养丰富的食品，以满足要幼儿生长发育对蛋白质和多种维生素的需求。进而改善农村地区婴幼儿营养状况。     

The relative bioavailability in humans of elemental iron powders for use in food fortification

Summary Background Bioavailability data in humans of elemental iron powders is limited although elemental iron is a common form of iron when used as a fortificant. Aim of the study The relative bioavailability (RBV) of seven elemental iron powders, five commercially available and two developmental are evaluated. In addition, one commercial electrolytic iron powder given with ascorbic acid (AA) was examined. Methods Based on a validated method this double–blinded randomized crossover study included three groups of male blood donors (n = 3*16) who were served rolls fortified with different elemental iron powders or ferrous sulfate (FeSO₄) nine weeks apart. Blood samples were drawn every hour for six hours. RBV was obtained by comparing the increase in serum iron concentration induced by the elemental iron with the increase induced by FeSO₄. Results All elemental iron powders studied were significantly less well absorbed compared to FeSO₄. The electrolytic iron given with 50–mg AA was as well absorbed as FeSO₄ (molar ratio = 1:6, AA:Fe). The mean RBVs of the iron powders were: electrolytic (A–131, RBV = 0.65); electrolytic (Electrolytic, RBV = 0.59); carbonyl (Ferronyl, RBV = 0.58); H–reduced (AC– 325, RBV = 0.56); H–reduced (Hi–Sol, RBV = 0.50); carbonyl (CF, RBV = 0.37); reduced (Atomet 95SP, RBV = 0.36). The reduced iron was distinguished by having significantly lower RBV (0.36) although no significant overall ranking was possible. Conclusion Based on a validated method this doubleblinded cross–over study in humans showed that the evaluated elemental iron powders currently available for commercial use are significantly less well absorbed compared to FeSO₄. The results indicate that the reduced iron powder was absorbed to a lower extent compared to the other iron powders and only 36% compared to FeSO₄. Ascorbic acid seems to improve the bioavailability of elemental iron even though a rather low molar ratio is used. Thus, if confirmed, this enhancing effect of ascorbic acid on elemental iron when used as a fortificant could be used by co–fortifying them.