Infantile thiamine deficiency in South and Southeast Asia: An age-old problem needing new solutions.

Infantile beriberi, a potentially fatal disorder caused by thiamine deficiency, is often viewed as a disease confined to history in regions of the world with predominant white rice consumption. Recent case reports have, however, highlighted the persistence of thiamine deficiency as a cause of infant mortality in South and Southeast Asia. Low infant thiamine status and incidence of beriberi is attributable to maternal thiamine deficiency and insufficient breast milk thiamine. Poor dietary diversity, food preparation and cooking practices and traditional post-partum food restrictions likely play a role in these high-risk regions. Given the contribution of thiamine deficiency to infant mortality and emerging evidence of long-lasting neurodevelopmental deficits of severe and even subclinical deficiency in early life, public health strategies to prevent thiamine deficiency are urgently needed. However, efforts are hampered by uncertainties surrounding the identification and assessment of thiamine deficiency, due to the broad non-specific clinical manifestations, commonly referred to as thiamine deficiency disorders (TDD), that overlap with other conditions resulting in frequent misdiagnosis and missed treatment opportunities, and secondly the lack of readily available and agreed upon biomarker analysis and cut-off thresholds. This review will discuss the key challenges and limitations in the current understanding of TDD and explore how ongoing initiatives plan to fill persistent knowledge gaps, namely in the development of a standardised case definition to help more accurately diagnose and treat TDD in low-resource settings. Given more attention and ensuring greater recognition of TDD will support the design and implementation of treatment and prevention programmes, and ensure beriberi can truly be considered 'the forgotten disease of Asia'.

Acceptability of complementary foods and breads prepared from zinc-fortified cereal flours among young children and adults in Senegal.

We completed a series of studies to assess the acceptability of zinc-fortified, cereal-based complementary foods and zinc-fortified wheat breads. Young children and their caregivers completed acceptability tests with complementary foods fortified with iron only (60 mg iron as ferrous fumarate per kilogram cereal flour), or the same level of iron and zinc (240 mg zinc as zinc oxide per kilogram cereal flour), and the caregivers completed triangle taste tests to compare the same products. A separate group of adult participants completed acceptability tests with wheat breads fortified with iron and folic acid (15 mg iron as ferrous fumarate per kilogram flour and 1.5 mg folic acid per kilogram flour) or the same levels of iron-folic acid and 2 levels of zinc (63 mg zinc or 126 mg zinc as zinc oxide per kilogram flour). Finally, a threshold test was administered to another group of adult participants to compare nonfortified wheat bread to breads fortified with zinc in 80 mg increments ranging from 80 to 400 mg zinc as zinc oxide per kilogram flour. All products were acceptable when compared to non-zinc-fortified equivalents, and were well liked by the respective participants. For the triangle tests, caregivers were not able to detect significant differences between products. For threshold tests, adult participants detected differences in breads prepared from fortified wheat flour at 80 mg, 160 mg, and 320 mg zinc per kilogram flour, but not at 240 mg and 400 mg zinc per kilogram flour, respectively, when compared to nonfortified bread equivalents. Zinc fortification of cereal flours in the ranges of fortification that were tested does not adversely affect the acceptability of complementary foods and breads prepared from these flours. Practical Application: Fortification of staple food products is a low-cost approach to deliver additional micronutrients (including zinc) to large segments of a population. Determining the acceptability of products fortified with zinc is an important step in the development of zinc fortification programs.

A national survey of iron and folate status in pregnant women in Switzerland.

Women often do not meet the increased iron and folate needs of pregnancy. Maternal iron-deficiency anemia is associated with poor maternal and infant outcomes, including preterm delivery and low birth weight. Poor folate status increases risk for maternal anemia, spontaneous abortion, and congenital defects. Because of this, supplemental iron and folate are often recommended during pregnancy. There are few data on iron and folate status in pregnant women in Switzerland. We measured iron and folate status in a national sample of Swiss pregnant women, estimated the prevalence of anemia, and determined if supplement use is associated with iron and/or folate status in this group. A 3-stage probability to size cluster sampling method was used to obtain a representative national sample of pregnant women (n = 381) in the second and third trimester. We measured hemoglobin, hematocrit, mean corpuscular volume, and serum folate and ferritin concentrations. Serum transferrin receptor concentration was determined in anemic subjects. The use of iron and folate supplements was evaluated by questionnaire. Mean hemoglobin (+/- SD) in the sample was 123 g/L (+/- 1.0). The prevalence of anemia was 6%. Of the 21 anemic women, 11 were iron-deficient, giving an iron-deficiency anemia prevalence of 3%. Nineteen percent of women had low serum ferritin concentrations (< 12 micrograms/L) and 4% had low serum folate concentration (< 2.5 micrograms/L). Supplements containing iron were taken by 65% of women, and 63% were taking folate-containing supplements. Women in the second and third trimester taking folate-containing supplements had significantly higher serum folate concentrations compared to those not taking a folate supplement (p < 0.001). In the third trimester, women taking iron-containing supplements had significantly higher serum ferritin concentrations compared to those not taking an iron-containing supplement (p < 0.01). Our findings indicate that iron and folate status appears to be adequate in the majority of pregnant women in Switzerland, and that use of iron and folate supplements may have a positive impact on status.

Monitoring the adequacy of salt iodization in Switzerland: a national study of school children and pregnant women.

BACKGROUND: Several countries with long-standing salt iodization programs, including Switzerland, have recently reported declining and/or low urinary iodine (UI) levels in their populations. In Switzerland, in response to studies indicating low UI levels in children and pregnant women, the salt iodine level was increased in 1998 from 15 to 20 mg/kg. OBJECTIVE: Our objective was to evaluate iodine nutrition in a national sample of Swiss school children and pregnant women 8 16 months after the increase in the salt iodine level. DESIGN: A 3-stage probability proportionate to size cluster sampling method was used to obtain a representative national sample of 600 children aged 6-12 y and 600 pregnant women. We then measured UI in both groups, thyrotropin (TSH) in pregnant women and thyroid volume by ultrasound to determine goiter prevalence in school children. RESULTS: The median UI (range) of the children and pregnant women was 115 microg/l (5-413) and 138 microg/l (5-1881), respectively. The median blood TSH concentration (range) of pregnant women was 0.6 mU/l (0.2-2.1). Based on the current WHO/ICCIDD normative data for thyroid volume, none of the children were goitrous, using either age/sex-specific or BSA/sex-specific cutoffs. CONCLUSIONS: The iodine status of the Swiss population is once again adequate, illustrating the value of periodic monitoring and prudent adjustments to the iodine level in salt. This approach could serve as a model for countries struggling to maintain dietary iodine intake in the face of shifting dietary habits and changes in the food supply.

A national study of the prevalence of overweight and obesity in 6-12 y-old Swiss children: body mass index, body-weight perceptions and goals.

OBJECTIVES: To estimate the prevalence of overweight and obesity in Swiss children and to obtain information on weight perceptions and weight control practices in this population. DESIGN: Cross-sectional, three-stage, probability-proportionate-to-size cluster sampling. SETTING: Middle schools throughout Switzerland. SUBJECTS: A representative national sample of 595 6-12 y-old schoolchildren. INTERVENTION: Measurement of weight and height; interview on weight perceptions and weight control practices. RESULTS: Body mass index (BMI) was calculated and used as an indicator of overweight. The BMIs of the Swiss children were compared with US, UK, French and Swiss reference data. Depending on which reference data were used, the prevalence of obesity varied between 9.7 and 16.1% and the prevalence of overweight varied between 21.7 and 34.2%. Girls were significantly more likely to consider themselves too fat (26% and 15%, respectively) and to report currently trying to lose weight (30% and 18%, respectively) compared to boys (P<0.05). CONCLUSIONS: The prevalence of overweight in Swiss children, and its attendant health and social consequences, are important public health concerns. SPONSORSHIP: The Swiss Foundation for Nutrition Research, Zürich, Switzerland.

Thyroid volumes in a national sample of iodine-sufficient swiss school children: comparison with the World Health Organization/International Council for the control of iodine deficiency disorders normative thyroid volume criteria.

OBJECTIVE: The determination of goiter prevalence in children by thyroid ultrasound is an important tool for assessing iodine deficiency disorders. The current World Health Organization/International Council for the Control of Iodine Deficiency Disorders (WHO/ICCIDD) normative values, based on thyroid volume in iodine-sufficient European children, have recently been questioned, as thyroid volumes in iodine-sufficient children from the USA and Malaysia are smaller than the WHO/ICCIDD reference data. Our objective was to describe ultrasonographic thyroid volumes in a representative national sample of iodine-sufficient Swiss school children, and to compare these with the current reference data for thyroid volume. DESIGN AND METHODS: A 3-stage, probability proportionate-to-size cluster sampling method was used to obtain a representative national sample of 600 Swiss children aged 6-12 years. The following data were collected: thyroid size by ultrasound, urinary iodine concentration, weight, height, sex and age. RESULTS: The median urinary iodine concentration (range) of the children was 115 microgram/l (5-413). Application of the WHO/ICCIDD thyroid volume references to the Swiss children resulted in a prevalence of 0%, using either age/sex-specific or body surface area (BSA)/sex-specific cut-off values. Upper limits of normal (97th percentile) of thyroid volume from Swiss children calculated using BSA, sex and age were similar to those reported in iodine-sufficient children in the USA, but were 20-56% lower than the corresponding WHO/ICCIDD references. CONCLUSIONS: Swiss children had smaller thyroids than the European children on which the WHO/ICCIDD references are based, perhaps due to a residual effect of a recent past history of iodine deficiency in many European regions. However, there were sharp differences between our data and a recent set of thyroid volume data in Swiss children produced by the operator and equipment that generated the WHO/ICCIDD reference data. This suggests that interobserver and/or interequipment variability may contribute to the current disagreement on normative values for thyroid size by ultrasound in iodine-sufficient children.

An evaluation of salt intake and iodine nutrition in a rural and urban area of the Côte d'Ivoire.

OBJECTIVE: To evaluate the habitual salt intake of individuals living in the Côte d'Ivoire, and to monitor the iodine nutrition of adults, schoolchildren and pregnant women one year after implementation of a universal salt iodisation programme. DESIGN: A three day weighed food records with estimation of food intake from a shared bowl based on changes on body weight, determination of sodium and iodine concentrations in 24 h (24 h) urine samples from adults, and determination of urinary iodine in spot urines from schoolchildren and pregnant women. SETTING: A large coastal city (Abidjan) and a cluster of inland villages in the northern savannah region of the Côte d'Ivoire. SUBJECTS: For the food records: 188 subjects (children and adults) in the northern villages; for the 24 h urine collections: 52 adults in Abidjan and 51 adults in the northern villages; for the spot urine collections: 110 children and 72 pregnant women in Abidjan and 104 children and 66 pregnant women in the north. MAIN RESULTS: From the food survey data in the north, the total mean salt intake (s.d.) of all age groups and the adults was estimated to be 5.7 g/d (+/- 3.0), and 6.8 g/d (+/- 3.2), respectively. In the 24 h urine samples from adults, the mean sodium excretion was 2.9 g/d (+/- 1.9) in the north and 3.0 g/d (+/- 1.3) in Abidjan, corresponding to an intake of 7.3-7.5 g/d of sodium chloride. In the north the median 24 h urinary iodine excretion in adults was 163 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 263 microg/l and 133 microg/l, respectively. In contrast, in Abidjan the median 24 h urinary iodine was 442 microg/d, with 40% of the subjects excreting > 500 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 488 microg/l and 364 microg/l, respectively. Nearly half of the children in Abidjan and 32% of the pregnant women were excreting > 500 microg/l. CONCLUSION: Based on the estimates of salt intake in this study, an optimal iodine level for salt (at the point of consumption) would be 30 ppm. Therefore the current goals for the iodised salt programme--30-50 ppm iodine appear to be appropriate. However, in adults, children and pregnant women from Abidjan, high urinary iodine levels--levels potentially associated with increased risk of iodine-induced hyperthyroidism--are common. These results suggest an urgent need for improved monitoring and surveillance of the current salt iodisation programme in the Côte d'Ivoire.