Universal Salt Iodisation: Lessons learned from Cambodia for ensuring programme sustainability.

Iodine deficiency is the leading cause of preventable intellectual disability in the world, but it has been successfully prevented in most countries through universal salt iodization (USI). In 2011, Cambodia appeared to be an example of this success story, but today, Cambodian women and children are once again iodine deficient. In 2011, Cambodia demonstrated high-household coverage of adequately iodized salt and had achieved virtual elimination of iodine deficiency in school-age children. However, this achievement was not sustained because the USI programme was dependent on external funding, and the national government and salt industries had not institutionalized their implementation responsibilities. Recent programmatic efforts, in particular the establishment of a regulatory monitoring and enforcement system, are turning the situation around. Although Cambodia has not yet fully regained the achievements of 2011 (only 55% of tested salt was adequately iodized in 2017 compared with 67% in 2011), the recent steps taken by the government and the salt industry point to greater sustainability of the USI programme and the long-term prevention of iodine deficiency in children, women, and the general population.

Household Consumption of Thiamin-Fortified Fish Sauce Increases Erythrocyte Thiamin Concentrations among Rural Cambodian Women and Their Children Younger Than 5 Years of Age: A Randomized Controlled Efficacy Trial.

OBJECTIVES: To assess whether ad libitum consumption of thiamin-fortified fish sauce over 6 months yields higher erythrocyte thiamin diphosphate concentrations (eTDP) among women of childbearing age and their children aged 12-59 months compared with control sauce containing no thiamin. STUDY DESIGN: In this double-blind, randomized controlled efficacy trial, 276 nonpregnant, nonlactating women (18-45 years of age) and their families in Prey Veng, Cambodia, were randomized to receive 1 of 3 fish sauce formulations: low thiamin concentration (low, 2 g/L), high thiamin concentration (high, 8 g/L), or a control (no thiamin) fish sauce. Baseline (t = 0) and endline (t = 6 months) eTDP were measured with the use of high-performance liquid chromatography with a fluorescence detector. RESULTS: Fish sauce consumption did not differ between treatment groups (P = .19). In intent-to-treat analysis, women's baseline-adjusted endline eTDP (mean; 95% CI) was higher among women in the low (259; 245-274 nmol/L) and high (257; 237-276 nmol/L) groups compared with control (184; 169-198 nmol/L; P < .001); low and high groups did not differ (P = .83). Similarly, children's baseline-adjusted eTDP was higher in the low (259; 246-271 nmol/L) and high (257; 243-270 nmol/L) groups compared with control (213; 202-224 nmol/L; P < .001). CONCLUSION: Fortified fish sauce appears to be an efficacious means of improving biochemical thiamin status in nonpregnant, nonlactating women and their children (1-5 years of age) living in rural Cambodia. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02221063.

Assessment of salt intake to consider salt as a fortification vehicle for thiamine in Cambodia.

Thiamine deficiency is a public health issue in Cambodia. Thiamine fortification of salt has been proposed; however, the salt intake of lactating women, the target population, is currently unknown. We estimated salt intakes among lactating women (<6 months postpartum) using three methods: repeat observed-weighed intake records and 24-h urinary sodium excretions (n = 104), and household salt disappearance (n = 331). Usual salt intake was estimated by adjusting for intraindividual intakes using the National Cancer Institute method, and a thiamine salt fortification scenario was modeled using a modified estimated average requirement (EAR) cut-point method. Unadjusted salt intake from observed intakes was 9.3 (8.3-10.3) g/day, which was not different from estimated salt intake from urinary sodium excretions, 9.0 (8.4-9.7) g/day (P = 0.3). Estimated salt use from household salt disappearance was 11.3 (10.7-11.9) g/person/day. Usual (adjusted) salt intake from all sources was 7.7 (7.4-8.0) g/day. Assuming no stability losses, a modeled fortification dose of 275 mg thiamine/kg salt could increase thiamine intakes from fortified salt to 2.1 (2.0-2.2) mg/day, with even low salt consumers reaching the EAR of 1.2 mg/day from fortified salt alone. These findings, in conjunction with future sensory and stability research, can inform a potential salt fortification program in Cambodia.

Thiamine supplementation holds neurocognitive benefits for breastfed infants during the first year of life.

Women reliant on mostly rice-based diets can have inadequate thiamine intake, placing breastfed infants at risk of thiamine deficiency and, in turn, physical and cognitive impairments. We investigated the impact of maternal thiamine supplementation doses on infants' cognitive, motor, and language development across the first year. In this double-blind, four-parallel-arm, randomized controlled trial, healthy mothers of exclusively breastfed newborn infants were recruited in Kampong Thom, Cambodia. At 2 weeks postnatal, women (n = 335) were randomized to one of four treatment groups to consume one capsule/day with varying amounts of thiamine for 22 weeks: 0, 1.2, 2.4, and 10 mg. At 2, 12, 24, and 52 weeks of age, infants were assessed with the Mullen Scales of Early Learning (MSEL) and the Caregiver Reported Early Development Instrument (CREDI). Multiple regression and mixed effects modeling suggest that by 6 months of age, the highest maternal thiamine dose (10 mg/day) held significant benefits for infants' language development, but generally not for motor or visual reception development. Despite having achieved standardized scores on the MSEL that approximated U.S. norms by 6 months, infants showed a significant drop relative to these norms in both language domains following trial completion, indicating that nutritional interventions beyond 6 months may be necessary.

Low-dose thiamine supplementation of lactating Cambodian mothers improves human milk thiamine concentrations: a randomized controlled trial.

BACKGROUND: Infantile beriberi-related mortality is still common in South and Southeast Asia. Interventions to increase maternal thiamine intakes, and thus human milk thiamine, are warranted; however, the required dose remains unknown. OBJECTIVES: We sought to estimate the dose at which additional maternal intake of oral thiamine no longer meaningfully increased milk thiamine concentrations in infants at 24 wk postpartum, and to investigate the impact of 4 thiamine supplementation doses on milk and blood thiamine status biomarkers. METHODS: In this double-blind, 4-parallel arm randomized controlled dose-response trial, healthy mothers were recruited in Kampong Thom, Cambodia. At 2 wk postpartum, women were randomly assigned to consume 1 capsule, containing 0, 1.2 (estimated average requirement), 2.4, or 10 mg of thiamine daily from 2 through 24 weeks postpartum. Human milk total thiamine concentrations were measured using HPLC. An Emax curve was plotted, which was estimated using a nonlinear least squares model in an intention-to-treat analysis. Linear mixed-effects models were used to test for differences between treatment groups. Maternal and infant blood thiamine biomarkers were also assessed. RESULTS: In total, each of 335 women was randomly assigned to1 of the following thiamine-dose groups: placebo (n = 83), 1.2 mg (n = 86), 2.4 mg (n = 81), and 10 mg (n = 85). The estimated dose required to reach 90% of the maximum average total thiamine concentration in human milk (191 µg/L) is 2.35 (95% CI: 0.58, 7.01) mg/d. The mean ± SD milk thiamine concentrations were significantly higher in all intervention groups (183 ± 91, 190 ± 105, and 206 ± 89 µg/L for 1.2, 2.4, and 10 mg, respectively) compared with the placebo group (153 ± 85 µg/L; P < 0.0001) and did not significantly differ from each other. CONCLUSIONS: A supplemental thiamine dose of 2.35 mg/d was required to achieve a milk total thiamine concentration of 191 µg/L. However, 1.2 mg/d for 22 wk was sufficient to increase milk thiamine concentrations to similar levels achieved by higher supplementation doses (2.4 and 10 mg/d), and comparable to those of healthy mothers in regions without beriberi. This trial was registered at clinicaltrials.gov as NCT03616288.

Thiamine dose response in human milk with supplementation among lactating women in Cambodia: study protocol for a double-blind, four-parallel arm randomised controlled trial.

INTRODUCTION: Thiamine (vitamin B1) deficiency remains a concern in Cambodia where women with low thiamine intake produce thiamine-poor milk, putting their breastfed infants at risk of impaired cognitive development and potentially fatal infantile beriberi. Thiamine fortification of salt is a potentially low-cost, passive means of combating thiamine deficiency; however, both the dose of thiamine required to optimise milk thiamine concentrations as well as usual salt intake of lactating women are unknown. METHODS AND ANALYSIS: In this community-based randomised controlled trial, 320 lactating women from Kampong Thom, Cambodia will be randomised to one of four groups to consume one capsule daily containing 0, 1.2, 2.4 or 10 mg thiamine as thiamine hydrochloride, between 2 and 24 weeks postnatal. The primary objective is to estimate the dose where additional maternal intake of thiamine no longer meaningfully increases infant thiamine diphosphate concentrations 24 weeks postnatally. At 2, 12 and 24 weeks, we will collect sociodemographic, nutrition and health information, a battery of cognitive assessments, maternal (2 and 24 weeks) and infant (24 weeks only) venous blood samples (biomarkers: ThDP and transketolase activity) and human milk samples (also at 4 weeks; biomarker: milk thiamine concentrations). All participants and their families will consume study-provided salt ad libitum throughout the trial, and we will measure salt disappearance each fortnight. Repeat weighed salt intakes and urinary sodium concentrations will be measured among a subset of 100 participants. Parameters of Emax dose-response curves will be estimated using non-linear least squares models with both 'intention to treat' and a secondary 'per-protocol' (capsule compliance ≥80%) analyses. ETHICS AND DISSEMINATION: Ethical approval was obtained in Cambodia (National Ethics Committee for Health Research 112/250NECHR), Canada (Mount Saint Vincent University Research Ethics Board 2017-141) and the USA (University of Oregon Institutional Review Board 07052018.008). Results will be shared with participants' communities, as well as relevant government and scientific stakeholders via presentations, academic manuscripts and consultations. TRIAL REGISTRATION NUMBER: NCT03616288.

Comparable Performance Characteristics of Plasma Thiamine and Erythrocyte Thiamine Diphosphate in Response to Thiamine Fortification in Rural Cambodian Women.

Background: Traditionally, vitamin B1 status is assessed by a functional test measuring erythrocyte transketolase (ETK) activity or direct measurement of erythrocyte thiamine diphosphate (eThDP) concentration. However, such analyses are logistically challenging, and do not allow assessment of vitamin B1 status in plasma/serum samples stored in biobanks. Using a multiplex assay, we evaluated plasma concentrations of thiamine and thiamine monophosphate (TMP), as alternative, convenient measures of vitamin B1 status. Methods: We investigated the relationships between the established biomarker eThDP and plasma concentrations of thiamine and TMP, and compared the response of these thiamine forms to thiamine fortification using samples from 196 healthy Cambodian women (aged 18-45 years.). eThDP was measured by high performance liquid chromatography with fluorescence detection (HPLC-FLD) and plasma thiamine and TMP by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: Plasma thiamine and TMP correlated significantly with eThDP at baseline and study-end (p < 0.05). Among the fortification groups, the strongest response was observed for plasma thiamine (increased by 266%), while increases in plasma TMP (60%) and eThDP (53%) were comparable. Conclusions: Plasma thiamine and TMP correlated positively with eThDP, and all thiamine forms responded significantly to thiamine intervention. Measuring plasma concentrations of thiamine forms is advantageous due to convenient sample handling and capacity to develop low volume, high-throughput, multiplex assays.

Correlations between Maternal, Breast Milk, and Infant Vitamin B12 Concentrations among Mother-Infant Dyads in Vancouver, Canada and Prey Veng, Cambodia: An Exploratory Analysis.

Vitamin B12 plays an essential role in fetal and infant development. In regions where animal source food consumption is low and perinatal supplementation is uncommon, infants are at risk of vitamin B12 deficiency. In this secondary analysis, we measured total vitamin B12 concentrations in maternal and infant serum/plasma and breast milk among two samples of mother-infant dyads in Canada (assessed at 8 weeks post-partum) and in Cambodia (assessed between 3-27 weeks post-partum). Canadian mothers (n = 124) consumed a daily vitamin B12-containing multiple micronutrient supplement throughout pregnancy and lactation; Cambodian mothers (n = 69) were unsupplemented. The maternal, milk, and infant total vitamin B12 concentrations (as geometric means (95% CI) in pmol/L) were as follows: in Canada, 698 (648,747), 452 (400, 504), and 506 (459, 552); in Cambodia, 620 (552, 687), 317 (256, 378), and 357 (312, 402). The majority of participants were vitamin B12 sufficient (serum/plasma total B12 > 221 pmol/L): 99% and 97% of mothers and 94% and 84% of infants in Canada and Cambodia, respectively. Among the Canadians, maternal, milk, and infant vitamin B12 were all correlated (p < 0.05); only maternal and infant vitamin B12 were correlated among the Cambodians (p < 0.001).

Perinatal Consumption of Thiamine-Fortified Fish Sauce in Rural Cambodia: A Randomized Clinical Trial.

IMPORTANCE: Infantile beriberi, a potentially fatal disease caused by thiamine deficiency, remains a public health concern in Cambodia and regions where thiamine-poor white rice is a staple food. Low maternal thiamine intake reduces breast milk thiamine concentrations, placing breastfed infants at risk of beriberi. OBJECTIVE: To determine if consumption of thiamine-fortified fish sauce yields higher erythrocyte thiamine diphosphate concentrations (eTDP) among lactating women and newborn infants and higher breast milk thiamine concentrations compared with a control sauce. DESIGN, SETTING, AND PARTICIPANTS: In this double-blind randomized clinical trial, 90 pregnant women were recruited in the Prey Veng province, Cambodia. The study took place between October 2014 and April 2015. INTERVENTIONS: Women were randomized to 1 of 3 groups (n = 30) for ad libitum fish sauce consumption for 6 months: control (no thiamine), low-concentration (2 g/L), or high-concentration (8 g/L) fish sauce. MAIN OUTCOMES AND MEASURES: Maternal eTDP was assessed at baseline (October 2014) and endline (April 2015). Secondary outcomes, breast milk thiamine concentration and infant eTDP, were measured at endline. RESULTS: Women's mean (SD) age and gestational stage were 26 (5) years and 23 (7) weeks, respectively. April 2015 eTDP was measured among 28 women (93%), 29 women (97%), and 23 women (77%) in the control, low-concentration, and high-concentration groups, respectively. In modified intent-to-treat analysis, mean baseline-adjusted endline eTDP was higher among women in the low-concentration (282nM; 95% CI, 235nM to 310nM) and high-concentration (254nM; 95% CI, 225nM to 284nM) groups compared with the control group (193nM; 95% CI, 164nM to 222M; P < .05); low-concentration and high-concentration groups did not differ (P = .19). Breast milk total thiamine concentrations were 14.4 µg/dL for the control group (95% CI, 12.3 µg/dL to 16.5 µg/dL) (to convert to nanomoles per liter, multiply by 29.6); 20.7 µg/dL for the low-concentration group (95% CI, 18.6 µg/dL to 22.7 µg/dL ); and 17.7 µg/dL for the high-concentration group (95% CI, 15.6 µg/dL to 19.9 µg/dL). Mean (SD) infant age at endline was 16 (8) weeks for the control group, 17 (7) weeks for the low-concentration group, and 14 (8) for the high-concentration group. Infant eTDP was higher among those in the high-concentration group (257nM; 95% CI, 222nM to 291nM; P < .05) compared with the low-concentration (212nM; 95% CI, 181nM to 244nM) and control (187nM; 95% CI, 155nM to 218nM) groups. CONCLUSIONS AND RELEVANCE: Compared with women in the control group, women who consumed thiamine-fortified fish sauce through pregnancy and early lactation had higher eTDP and breast milk thiamine concentrations and their infants had higher eTDP, which was more pronounced in the high group. Thiamine-fortified fish sauce has the potential to prevent infantile beriberi in this population. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT02221063.