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U.S. Department of Agriculture/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, 77030;
* The Princess Marina Hospital, Gaborone, Botswana; and
Program in International Nutrition, University of California Davis, Davis, CA 95616
3To whom correspondence should be addressed. E-mail: sabrams{at}bcm.tmc.edu.
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ABSTRACT |
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 TOP ABSTRACT SUBJECTS AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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KEY WORDS: • Africa • fortified beverage • micronutrient deficiency • undernutrition
Micronutrient deficiencies, particularly those involving iron, zinc, folic acid, vitamin B-12 and vitamin A, remain major problems for children in many countries (1). These deficiencies not only contribute to delays in growth and development, but are also important factors in the transmission and progression of infectious diseases (2,3). However, pill or liquid micronutrient supplementation programs have not demonstrated long-term effectiveness, possibly due to problems in distribution or lack of public acceptance of this approach.
Governments and nongovernmental agencies are increasingly considering food fortification with micronutrients as an alternative approach to resolving micronutrient deficiencies. Staple foods such as flour are often fortified with iron and folic acid, and the addition of other nutrients, such as zinc, is being considered in many countries. However, no single fortified food is likely to provide an adequate intake of supplemental minerals, and many foods contain inhibitors of nutrient absorption. Therefore, additional strategies must be considered. A potential approach is the development of a micronutrient-fortified liquid beverage that could be introduced into both the marketplace and school feeding programs. This strategy has the dual benefit of reaching a wide cross section of consumers while providing a supplement perceived to be an enjoyable, as well as a healthy alternative to other, nutritionally inferior, beverages. However, before this approach can be advocated, such products must be evaluated for their effects on the growth and nutritional status of at-risk populations, as well as for consumer acceptance.
Primarily due to technical difficulties, few beverages have provided the required nutrients, adequate stability and an acceptable taste. After successful taste and stability tests, we conducted a double-blind plausibility trial to investigate the effects of a newly developed multinutrient-fortified beverage on measures of anthropometric, hematologic and biochemical indices of nutritional status in young children. The study was conducted in a geographically well-defined and socially homogeneous population in which, on the basis of earlier surveys, nutrient deficiencies and delayed growth were known to occur, but also one in which resources were available for inclusion of the fortified beverage into a comprehensive intervention program or for consumption in the home.
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SUBJECTS AND METHODS |
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TOPABSTRACTSUBJECTS AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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This study was conducted in two public schools on the outskirts of Gaborone, the capital of the southern African country of Botswana. On the basis of input from local medical and educational officials, it was determined that there was a substantial risk of confusing the beverages by attempting to provide more than one drink at each school, and that maintaining blinding would then be nearly impossible. Two schools were required to provide an adequate number of subjects for the trial. Therefore, we found two schools with similar baseline characteristics, so that all subjects could be considered equivalent, independent of the school they attended. All students in one school were provided the experimental beverage, whereas the control beverage was given at the other school. By assigning the subjects to either the fortified beverage or control, using their school for assignment, we hoped to be able to avoid compromising the study by an error in administration, while still obtaining meaningful results. Limitations of this approach are considered in the Discussion.
Before starting the study, information was collected to confirm that there were no noteworthy differences in characteristics between the children in the two schools or in their environment that might cause confounding. The schools were located within 1.6 km of each other geographically, and the school districts were contiguous. The children in both schools represented a socioeconomically homogenous population from lower income, urban families whose homes received water delivered from the same system. The school buildings were structurally similar, without central air conditioning or heat, and had no obvious sources of external contamination. Interviews conducted with a sample of five mothers of children attending each of the schools did not reveal any notable dietary differences between the two groups. The meals served by the families to the children were similar; many of the mothers shopped at the same stores. At both schools, the children were served a noon meal consisting of a "porridge" called Tsabana made from sorghum and beans, which was prepared each morning on site in large pots. This mixture also constituted a large portion of the energy intake of the children at home, remaining a staple throughout the year. The baseline anthropometric and biochemical studies supported the equivalence of the two groups (see Results section).
Children were to receive an average of 240 mL daily of the fortified beverage or placebo under direct observation for 8 wk. Study investigators and subjects were unaware of the identity of the product administered at each school.
Review and approval of the protocol were obtained from the Baylor College of Medicine Institutional Review Board, the Ethics and Study Committee of The Princess Marina Hospital in Gaborone, Botswana, the Ministry of Health of Botswana, the Human Subjects Research Committee at the University of California, Davis and the Scientific Advisory Committee of the Secure the Future Program, a philanthropic organization conducting research studies in southern Africa. Informed written consent was obtained from the family of each participant, using consent forms in both English and the native language, Setswana. Children were considered eligible for the study if they were 5–11 y old, weighed >15 kg, had a hemoglobin concentration > 60 g/L and had no known chronic illnesses such as HIV or recent acute illnesses (including diarrhea or a respiratory infection). Earlier surveys in Botswana showed a mean hemoglobin concentration in children of 112 ± 18 g/L and a prevalence of hemoglobin concentration < 110 g/L of 38% (4). Routine HIV testing of study subjects was not deemed ethically appropriate by local physicians or human use committees, and was not performed.
Any child with abnormal findings on physical examination was referred to the local hospital for diagnosis and treatment. Two children suspected of having HIV/acquired immunodeficiency syndrome, on the basis of their physical exam findings, were sent for testing, were found to be positive and were referred for further evaluation. In accordance with the entry criteria, these children were excluded from the study. Although the prevalence of HIV infection is high among young adults in Botswana, it is unlikely there were substantially more unidentified HIV-positive subjects. Most children who are vertically infected will be symptomatic by age 5, and the risk of exposure in the age group studied remains low until the child becomes sexually active.
Of the 311 children enrolled (164 in the experimental fortified beverage [EXP] group and 147 in the isoenergetic placebo beverage [CON] group), 145 in the treatment group (EXP) and 118 in the control group (CON) completed the trial. Five children were found to have failed entry criteria after enrollment, 34 were lost to follow-up, samples were misplaced from 8, and 1 subject refused phlebotomy. The difference in dropout rates between groups (11.5% in the EXP group and 19.7% in the CON group) resulted primarily from all misplaced samples occurring in the CON group. There were no significant differences in baseline characteristics between subjects who completed the study and those who did not.
Clinical protocol.
At the time of enrollment, the study physicians administered a brief medical history and physical examination. Anthropometric measurements were performed by a small group of trained physicians and nurses from The Princess Marina Hospital in Gaborone and Baylor College of Medicine. Baseline blood samples were obtained by peripheral venous phlebotomy and analyzed for hemoglobin, serum ferritin, retinol, folate, vitamin B-12 and the erythrocyte glutathione reductase activity coefficient (EGRAC) assay for riboflavin status. Samples at baseline for plasma zinc were found to be contaminated and were discarded. Repeat studies were performed at the completion of the protocol 8 wk later. Plasma zinc was obtained at that time using certified zinc-free tubes. Additionally, blood was obtained for serum transferrin receptor analysis at the final blood draw.
After the baseline anthropometric measurements and phlebotomy were performed, blood samples were analyzed immediately for hemoglobin concentration. It was confirmed that the students in the two schools had comparable anthropometry [weight-for-age and height-for-age Z-scores and mid-upper arm circumference (MUAC)] and hemoglobin concentration at the start of the study.
Intervention.
The EXP treatment group received a fruit-flavored beverage containing 419 kJ/240 mL with a proprietary blend of micronutrients (Table 1). The CON group received the same beverage without micronutrients. The manufacturer analyzed the micronutrient content of each beverage before administration. Both drinks were provided as a powder that was mixed to a 240-mL serving using bottled water containing negligible amounts of the nutrients of interest. Subjectively, neither students nor study personnel could identify the drinks on the basis of taste or appearance.
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2 h after breakfast and 2 h before lunch. Children who were absent from school received "catch-up" drinks when they returned, but never were given >2 drinks/d. Analysis of samples.
Hemoglobin concentration was initially measured using a Coulter counter at the Princess Marina Hospital in Gaborone. At the time of the follow-up visit, this equipment was not functioning, and measurements were performed on a different Coulter counter at the Private Hospital, Gaborone, Botswana. Hemoglobin values < 120 g/L were considered below normal in our statistical analysis.
Retinol was measured using HPLC (Shimadzu, Kyoto, Japan). Children were considered vitamin A–deficient if their retinol level was <0.7 µmol/L (20 pg/mL). A solid-phase, two-site fluoroimmunometric assay (DELFIA method, Perkin Elmer, Boston, MA) was utilized to determine ferritin concentrations, defined as deficient if <33.7 pmol/L (15.0 µg/L). Serum soluble transferrin receptor levels were measured using an ELISA (Quantikine, R&D Systems, Minneapolis, MN). Folate and vitamin B-12 levels were measured by RIA (Diagnostic Products, Los Angeles, CA) with a cut-off value for deficiency of 13.4 nmol/L (5.9 µg/L) and 147.6 pmol/L (200 pg/L), respectively. Atomic absorption spectrophotometry (Perkin Elmer, Norwalk, CT) was used to determine zinc concentrations (deficient if <10 µmol/L or 0.85 µg/dL). EGRAC was performed as described by Sauberlich (5) using a Thermo Labsystems well-plate reader (Franklin, MA), with riboflavin deficiency defined as an EGRAC 
1.4
Statistical and power analysis.
Initial planning called for 282 children to complete the study to achieve a power of 0.90 to detect a relative increase in hemoglobin of 5 g/L in the EXP group. A few additional subjects were screened at each school due to the desire of the school administration and students to participate. Descriptive statistics of baseline data (Tables 2and 3), contingency table analysis, and power analysis utilized Minitab Release 13.1 (Minitab, State College, PA). The STATA 6.0 software package (STATA, College Station, TX) was utilized for the analysis of covariance (ANCOVA) for multivariate analysis, for linear regression of two continuous variables and for binary logistic regression. Values of P < 0.05 were considered significant. Anthropometric data were analyzed using the ANTHRO software distributed by the U.S. Centers for Disease Control and Prevention (6).
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RESULTS |
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TOPABSTRACTSUBJECTS AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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13 L consumed). Anthropometric data.
The anthropometric measurements obtained during enrollment demonstrate the similarities of the two groups (Table 2). Children in the EXP group were 5.4 mo older than children in the CON group. Correction of the anthropometric data for age using the WHO reference tables (7) showed that the two groups were nearly identical in terms of weight-for-age and weight-for-height Z-scores. Twenty-five children (8.4%) showed stunting with a height-for-age Z-score of less than -2 (12 in the EXP group and 13 in the CON group), and three of these subjects demonstrated severe stunting with a Z-score of less than -3 (all in group CON). Twenty subjects (6.7%) showed wasting, with weight-for-age Z-scores of less than –2 (11 in the EXP group and 9 in the CON group), with one student in the CON group having a Z-score of less than -3.
ANCOVA, adjusting for sex, age, group and weight, was used to analyze the mean change from baseline in growth variables in each cohort and the level of significance of the differences between the groups (Table 4). The changes in body mass index, MUAC, weight and weight-for-age Z-score differed between the groups (P < 0.01) and were more favorable in the EXP group.
Hematologic data.
The homogeneity of the two groups at study entry included similarities in the baseline hematologic data. Values for hemoglobin, ferritin and RBC indices were closely matched in the two groups (Table 2). The prevalence of low hemoglobin was also similar in the two groups. Hemoglobin < 120 g/L was seen in 11% (EXP) and 13% (CON) of the subjects (Table 3). Similarly, the prevalence of ferritin concentrations < 33.7 pmol/L was 11% (EXP) and 8% (CON) (P > 0.2).
Changes in hemoglobin, mean corpuscular volume and serum ferritin during the study were analyzed by ANCOVA, adjusting for age, sex, group and weight (Table 4). Changes in all three variables were significantly different between the EXP and CON groups, and in each case favored the EXP group (Table 4). As noted above (Subjects and Methods), the baseline and final complete blood counts were performed on two different machines. The hemoglobin concentration was slightly lower overall in both groups at the end of the study, but the measured decline was significantly lower in the EXP group than in the CON group (P < 0.001). Both serum ferritin (Table 4) and serum transferrin receptor concentration (5.6 ± 1.6 g/L n = 140 vs. 6.8 ± 1.9 n = 131, P < 0.01) at the end of the study were significantly better in the EXP group than in the CON group.
The prevalence of low values for hemoglobin, mean corpuscular volume (MCV) and ferritin was significantly less common at the end of the study in the EXP group than in the CON group (Table 3). Similarly, when odds ratios were calculated and adjusted for weight, age and sex, subjects in the EXP group were significantly less likely to have a low hemoglobin concentration (Table 5). The odds ratio for low serum ferritin was not significant (P = 0.14).
Biochemical data.
Biochemical indices of nutritional status were similar between the two groups at study entry (Table 2), as was the prevalence of folate, vitamin B-12, riboflavin and retinol deficiency (Table 3). Notably, 17 children in the EXP group (11.6%) and 17 children in the CON cohort (12.1%) showed evidence of both low iron stores (Hb < 120 g/L or ferritin < 33.7 pmol/L) and at least one other biochemical marker of micronutrient deficiency. These findings confirm the presence of multiple nutritional deficiencies in this population, as well as the similarities between the two schools.
There was no difference in the prevalence of deficiencies in folate, vitamin B-12, retinol or riboflavin between the groups at study entry (Table 3). However, by the end of the study, both low folate and low riboflavin status were significantly less common in the EXP group than in the CON group (Table 3). Retinol deficiency was common at both the start and at the end of the study, and did not differ between the EXP and CON groups. At study completion, low zinc levels were significantly more common in the CON cohort than the EXP group (Table 3). Baseline zinc values were not available.
Changes in biochemical data were assessed using ANCOVA, adjusting for age, sex, group and weight. The folate and riboflavin status, but not vitamin B-12, improved in the EXP group (P < 0.01). Serum zinc was higher at study end in the EXP group compared with the CON group (0.13 ± 0.02 µmol/L n = 130 vs. 0.12 ± 0.02 n = 124, P < 0.01). The odds of low zinc, folate and riboflavin status were significantly lower in the EXP group than in the CON group at study end (Table 5).
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DISCUSSION |
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TOPABSTRACTSUBJECTS AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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Anthropometric data.
The two groups were comparable at study entry, with 8.4% of the study population having a height-for-age Z-score less than -2, and 6.7% having a weight-for-age Z-score less than -2. By the end of the study, the change in weight, weight-for-age Z-score, body mass index and MUAC differed significantly between the EXP and CON groups. In each case, the change favored the EXP group.
The improved growth in the EXP group was not due to higher energy intake from the beverage itself because both the intervention and control beverage provided 419 kJ/child daily. But there are other potential explanations. One of the cardinal features of zinc deficiency is growth failure; thus, it is possible that the increase in zinc intake facilitated an augmented lean tissue accretion or increased utilization of the energy provided. Such a response of MUAC was described in zinc-supplemented Ugandan preschool children (8). The concept of "hidden hunger" associated with micronutrient deficiency has been described in recent years (9), and this may provide an alternative explanation for the improvement in growth. Lawless et al. (10) reported improvements in growth and appetite in Kenya as a result of iron supplementation on the basis of the results of an appetite test and questionnaires. Kanani and Poojara (11) reported improvement in growth in adolescent Indian girls who were given folic acid and iron supplementation. It is therefore possible that the EXP group may have had higher energy intakes as a result of increased appetite from improvements in their folate and iron status. Alternatively, improvement in iron stores, serum folate concentrations and enhanced zinc status may also be important in limiting morbidity, which can lead to improved growth variables, especially in at-risk children in developing countries.
Hematologic data.
The two groups had similar hematologic status at study entry. By study completion, the EXP group had significantly higher hemoglobin, and a lower prevalence of deficiency in hemoglobin, serum ferritin and low mean corpuscular volume than those in the CON group. As noted above, the prevalence of low hemoglobin concentration increased significantly in both groups. However, the initial and final hemoglobin measurements were made on different machines due to failure of the Coulter counter used at baseline. We speculate that the discrepancy in baseline and final hemoglobin concentrations reflected differences in calibration between the two machines, rather than a true decline in hemoglobin during the study. The prevalence of low hemoglobin in the CON group at study end is closer to our expectation in this population than the baseline values.
Serum transferrin receptor levels suggested better iron status in the EXP group than in the CON group at study end. Baseline data were unavailable; however, no other index of hematologic or iron status differed between the groups at study entry; thus, it is unlikely that serum transferrin receptors differed. The significant improvement in serum ferritin and mean corpuscular volume in the EXP group indicates a positive change in underlying iron status.
Biochemical data.
At the start of the study, low folate, retinol and riboflavin values were relatively common. Deficiencies in folate and riboflavin were much less prevalent in the EXP group than in the CON group by study end. At the completion of the trial, only 1% of children in EXP had low folate, compared with 22% of the subjects in the CON group. There are few data on the folate status of children in developing countries or on its functional consequences (12). Riboflavin is an important cofactor in the maintenance of normal levels of hemoglobin. A study performed in Thailand found that 40–80% of schoolchildren had riboflavin deficiency (13). Trials have demonstrated greater improvement in iron status when supplementation includes riboflavin and iron rather than iron alone (14,15). Using an EGRAC 1.4 as an indicator of riboflavin deficiency, the EXP and CON groups had a baseline prevalence of 40 and 33%, respectively. At the end of the study, the riboflavin status of the EXP group had improved (P < 0.001) with an odds ratio for deficiency of 0.36 (confidence interval 0.21 to 0.63) compared with the CON group.
We could not identify a positive effect of the beverage on serum retinol concentrations, despite the high prevalence of deficiency at the start of the study. The use of retinyl palmitate, rather than ß-carotene as the source of vitamin A, might have produced a greater effect on serum retinol. However, retinyl palmitate is less stable and more difficult to integrate into a beverage product than ß-carotene. It also has a greater potential for toxicity. The total amount of ß-carotene might have been inadequate to increase levels in the EXP group. Because of differences in converting ß-carotene to retinol among individuals, this issue remains controversial. Some authors suggest that the ratio of ß-carotene consumed to "retinol equivalents" (the amount of ß-carotene required to provide 1 µg of retinol) should be much greater than the 6:1 that was previously assumed (16). Depending on the type of food, estimates for the conversion ratio range from 2:1 to 24:1. Table 1, which shows the recommended dietary allowance (RDA) of each nutrient in the beverage, uses a conversion ratio of 12:1 based on the 2001 RDA published by the Institute of Medicine (17).
Vitamin B-12 deficiency was uncommon in this population, and the changes noted during the study did not differ significantly between the two groups. The percentage of vitamin B-12–deficient children in this sample from Botswana was substantially lower than that observed in other countries (18–20). This is quite surprising, given that the average consumption of meat, the major source of vitamin B-12 in the diet, is low; only 10% of households reported eating meat, poultry or fish daily (4). This implies that there may be an unexpected source of vitamin B-12 in the diet, perhaps from some of the traditional foods, or that lower rates of Helicobacter pylori infection or bacterial overgrowth exist, which can impair vitamin B-12 absorption.
The prevalence of zinc deficiency was significantly lower in the EXP cohort than the CON group at the end of the study. Although we did not have baseline plasma zinc values, it is unlikely that they differed between groups at baseline, given the homogeneity of the diet and other nutritional indices. Differences observed at the end of the study strongly suggest a beneficial effect on zinc status from consumption of the fortified beverage. This may be clinically important, leading to enhanced growth and decreased morbidity and mortality from infectious diseases in developing countries (2,3,21–23).
Use of fortified beverages.
There are some theoretical disadvantages to using sweetened beverages to deliver micronutrients to children. First, this strategy might increase children’s preference for sweet drinks, although there is little hard evidence that this is the case for school-aged children. It is unlikely that other nutritious beverages, such as milk or fresh juice, would be readily available to children in low-income families in developing countries because of their higher cost. A second concern is that the sugar might increase the risk of tooth decay, but this is unlikely due to the short period of time that beverages are in contact with the teeth. The third concern is that children may become overweight if they consume such beverages on a consistent basis. This may be true if the fortified beverages do not substitute for any other sources of energy in the diet, but is not a major concern in our study population. It is also possible to produce low calorie versions of this beverage if desired. Overall, because the current product is well liked by children, it conveys the great advantage that it is more likely to be consumed more consistently than micronutrient supplements. Weighing the apparent advantages from the higher micronutrient intake against the potential disadvantages of the product, the benefit:risk ratio is probably high, especially in populations with high rates of micronutrient deficiencies.
There are few comparable data regarding the efficacy of beverage products for improving nutritional status. A drink fortified with similar levels of nutrients was tested in 830 Tanzanian children. In that trial, the children in a primary school were given 200 mL of fortified beverage or placebo during each school day for 6 mo. It was reported that the odds ratio for anemia was 0.57 after treatment, and that the average ferritin concentrations increased 40.4 pmol/L in subjects given a fortified beverage vs. 4.5 pmol/L in those given an unfortified beverage (19,20). These findings are similar to the results reported here in our 8-wk trial. The results of both studies demonstrate that supplementation by means of a fortified beverage can be quite effective in improving iron status and decreasing the prevalence of anemia.
Although safety was not specifically evaluated in our trial, the beverage was well tolerated by the children. The levels of most micronutrients, including iron in these beverages, are far below the established upper safe intake levels in the United States. It should be emphasized that this beverage is intended for single or twice daily consumption rather than as a sole source of daily fluid, such as would be provided by a rehydration formula (17).
Although these results are promising, further evaluation is necessary to test the drink’s effectiveness in long-term field trials. Our study was significantly limited by the inclusion of only two schools. Although our results are likely to reflect the true benefit of the beverage, definitive randomized, placebo-controlled, double-blind studies in multiple schools (or other units) using fortified beverages over an extended period in a resource-poor setting should be conducted. These studies should also include assessment of long-term neuropsychological function.
In conclusion, this study demonstrated that compared with a control beverage, regular consumption of a micronutrient-fortified beverage for 8 wk led to improvements in weight, MUAC and several measures of micronutrient status in periurban school children in Botswana. The efficacy of this beverage in improving growth and micronutrient status indicates that fortified drinks may be a useful addition to supplementation strategies. The use of multiple fortification strategies, which includes fortified beverages, has several advantages. These include ease of distribution, high levels of acceptance, the ability to provide the beverage isolated from meals containing substances such as phytates, which can inhibit nutrient absorption, and the potential for purchase by private consumers rather than reliance on government programs.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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2 This work is a publication of the U.S. Department of Agriculture (USDA)/Agricultural Research Service (ARS) Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX. This project was financed in part with federal funds from the USDA/ARS under Cooperative Agreement number 58–6250-6–001 and by The Minute Maid Company, Houston, TX. Contents of this publication do not necessarily reflect the views or policies of the USDA, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.
4 S. A. Abrams and L. Allen are scientific consultants for the Minute Maid Company, which produced the beverage used in this research study.
5 Abbreviations used: ANCOVA, analysis of covariance; CON, isoenergetic placebo beverage; EGRAC, erythrocyte glutathione reductase activity coefficient; EXP, experimental fortified beverage; MUAC, mid-upper arm circumference; RDA, recommended dietary allowance.
Manuscript received 2 November 2002. Initial review completed 10 December 2002. Revision accepted 3 March 2003.
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LITERATURE CITED |
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TOPABSTRACTSUBJECTS AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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1. Stephenson, L. S., Latham, M. C. & Ottesen, E. A. (2000) Global malnutrition. Parasitology 121:S5-S22.
2. Sazawal, S., Black, R. E., Jalla, S., Mazumdar, S., Sinha, A. & Bhan, M. K. (1998) Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial. Pediatrics 102:1-5.
3. Hambidge, M. & Krebs, N. (1999) Zinc, diarrhea, and pneumonia. J. Pediatr. 135:661-664.[Medline]
4. Belbase, K., Khulumani, P., Maruapula, S. D., Mphathiwa, M. & Phegelo, M. (1996) Micronutrient Malnutrition in Botswana, a National Survey to Assess the Status of Iodine, Iron, and Vitamin A. Technical Report 1996 Food and Nutrition Unit, Family Health Division, Ministry of Health and the United Nations Children’s Fund .
5. Sauberlich, H. E. (1999) Laboratory Tests for the Assessment of Nutritional Status 1999 CRC Press Boca Raton, FL.
6. World Health Organization Expert Committee on Physical Status (1995) Physical Status: The Use and Interpretation of Anthropometry. WHO Technical Report Series no. 854 1995 WHO Geneva, Switzerland.
7. Kuczmarski, R. J., Ogden, C. L. & Grummer-Strawn, L. M. (2000) CDC Growth Charts: United States. Advance Data from Vital and Health Statistics, no. 314. (with errata). 2000 National Center for Health Statistics Hyattsville, MD.
8. Kikafunda, J. K., Walker, A. F., Allan, E. F. & Tunwine, J. K. (1998) Effect of zinc supplementation on growth and body composition of Ugandan preschool children: a randomized, controlled, intervention trial. Am. J. Clin. Nutr. 68:1261-1266.[Abstract]
9. Maberly, G. F., Trowbridge, F. L., Yip, R., Sullivan, K. M. & West, C. E. (1994) Programs against micronutrient malnutrition: ending hidden hunger. Annu. Rev. Public Health 15:277-301.[Medline]
10. Lawless, J. W., Latham, M. C., Stephenson, L. S., Kinoti, S. N. & Pertet, A. M. (1994) Iron supplementation improves appetite and growth in anemic Kenyan primary school children. J. Nutr. 124:645-654.
11. Kanani, S. J. & Poojara, R. H. (2000) Supplementation with iron and folic acid enhances growth in adolescent Indian girls. J. Nutr. 130:452S-455S.[Medline]
12. Allen, L. H. & Casterline-Sabel, J. (2000) Prevalence and causes of nutritional anemias. Ramakrishnan, U. eds. Nutritional Anemias 2000 CRC Press Baton Rouge, LA. .
13. Nontasut, P. (1996) Vitamin B1, B2, and B6 deficiency in primary school children infected with hookworm. Southeast Asian J. Trop. Med. Public Health 27:47-50.[Medline]
14. Bates, C. J., Prentice, A. M., Paul, A. A., Sutcliffe, B. A., Watkinson, M. & Whitehead, R. G. (1981) Riboflavin status in Gambian pregnant and lactating women and its implications for RDAs. Am. J. Clin. Nutr. 34:928-935.
15. Powers, H. J., Weaver, L. T., Austin, S., Wright, A. J. A. & Fairweather-Tait, S. J. (1991) Riboflavin deficiency in the rat: effects on iron utilization and loss. Br. J. Nutr. 65:487-496.[Medline]
16. West, C. E. (2000) Meeting requirements for vitamin A. Nutr. Rev. 58:341-345.[Medline]
17. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2001) Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc 2001 Food and Nutrition Board. Institute of Medicine. National Academy Press Washington, DC.
18. Allen, L. H., Rosado, J. L., Casterline, J. E., Martinez, H., López, P., Muñoz, P. E. & Black, A. K. (1995) Vitamin B-12 deficiency and malabsorption are highly prevalent in rural Mexican communities. Am. J. Clin. Nutr. 62:1013-1019.
19. Ash, D. M., Tstale, S. R., Frongillo, E. A., Ndosai, O. D., Msbamsba, H. & Latham, M. C. (1998) Trial of a micronutrient dietary supplement to control vitamin A, iron, and iodine deficiencies in Tanzania. FASEB J. 12:A648(abs.).
20. Ash, D. M., Tstale, S. R., Frongillo, E. A., Ndosai, O. D. & Latham, M. C. (1999) Effect of a micronutrient fortified beverage on anemia and stunting in Tanzanian school children. FASEB J. 13:A207(abs.).
21. Ruel, M. T., Rivera, J. A., Santizo, M. C., Lönnerdal, B. & Brown, K. H. (1997) Impact of zinc supplementation on morbidity from diarrhea and respiratory infections among rural Guatemalan children. Pediatrics 99:808-813.
22. Rivera, J. A., Ruel, M. T., Santizo, M. C., Lönnerdal, B. & Brown, K. H. (1998) Zinc supplementation improves the growth of stunted rural Guatemalan infants. J. Nutr. 128:556-562.
23. Black, R. E. (1998) Therapeutic and preventive effects of zinc on serious childhood infectious diseases in developing countries. Am. J. Clin. Nutr. 68(suppl.):476S-479S.[Abstract]
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 L. H. Allen, J. M. Peerson, and D. K. Olney Provision of Multiple Rather Than Two or Fewer Micronutrients More Effectively Improves Growth and Other Outcomes in Micronutrient-Deficient Children and Adults J. Nutr., May 1, 2009; 139(5): 1022 - 1030. [Abstract] [Full Text] [PDF]
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T. T. Nga, P. Winichagoon, M. A. Dijkhuizen, N. C. Khan, E. Wasantwisut, H. Furr, and F. T. Wieringa Multi-Micronutrient-Fortified Biscuits Decreased Prevalence of Anemia and Improved Micronutrient Status and Effectiveness of Deworming in Rural Vietnamese School Children J. Nutr., May 1, 2009; 139(5): 1013 - 1021. [Abstract] [Full Text] [PDF]
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S. M. Ziauddin Hyder, F. Haseen, M. Khan, T. Schaetzel, C. S. B. Jalal, M. Rahman, B. Lonnerdal, V. Mannar, and H. Mehansho A Multiple-Micronutrient-Fortified Beverage Affects Hemoglobin, Iron, and Vitamin A Status and Growth in Adolescent Girls in Rural Bangladesh J. Nutr., September 1, 2007; 137(9): 2147 - 2153. [Abstract] [Full Text] [PDF]
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E. D. McLean, L. H. Allen, C. G. Neumann, J. M. Peerson, J. H. Siekmann, S. P. Murphy, N. O. Bwibo, and M. W. Demment Low Plasma Vitamin B-12 in Kenyan School Children Is Highly Prevalent and Improved by Supplemental Animal Source Foods J. Nutr., March 1, 2007; 137(3): 676 - 682. [Abstract] [Full Text] [PDF]
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L. H. Allen New Approaches for Designing and Evaluating Food Fortification Programs J. Nutr., April 1, 2006; 136(4): 1055 - 1058. [Abstract] [Full Text] [PDF]
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D. Short When science met the consumer: the role of industry Am. J. Clinical Nutrition, July 1, 2005; 82(1): 256S - 258S. [Abstract] [Full Text] [PDF]
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E. Villamor, E. Saathoff, R. J Bosch, E. Hertzmark, A. Baylin, K. Manji, G. Msamanga, D. J Hunter, and W. W Fawzi Vitamin supplementation of HIV-infected women improves postnatal child growth Am. J. Clinical Nutrition, April 1, 2005; 81(4): 880 - 888. [Abstract] [Full Text] [PDF]
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M. Hettiarachchi, D. C. Hilmers, C. Liyanage, and S. A. Abrams Na2EDTA Enhances the Absorption of Iron and Zinc from Fortified Rice Flour in Sri Lankan Children J. Nutr., November 1, 2004; 134(11): 3031 - 3036. [Abstract] [Full Text] [PDF]
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U. Ramakrishnan, N. Aburto, G. McCabe, and R. Martorell Multimicronutrient Interventions but Not Vitamin A or Iron Interventions Alone Improve Child Growth: Results of 3 Meta-Analyses J. Nutr., October 1, 2004; 134(10): 2592 - 2602. [Abstract] [Full Text] [PDF]
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 M. Dubik Oral Zinc Supplement Reduces Duration of Severe Pneumonia AAP Grand Rounds, September 1, 2004; 12(3): 26 - 26. [Full Text] [PDF]
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