A Review of Vitamin A Supplementation in South Sudan: Successes, Challenges, and Opportunities for the Way Forward

Although South Sudan's vitamin A supplementation program has demonstrated success, vitamin A supplementation remains a critical public health need for young children. How can South Sudan best maintain high vitamin A supplementation coverage for the short to medium term while planning a more sustainable delivery approach for the longer term?

Aim:

To identify vitamin A supplementation (VAS) trends in South Sudan and provide insights to refocus VAS programming vis a vis polio eradication campaigns recently phased out while access to health care, land, food, and markets remain challenging.

Method:

Review of data from survey and coverage reports; review of policy and program documents; key informant responses; general literature search.

Results:

Vitamin A deficiency (VAD) is likely a severe public health problem among preschool-aged children in South Sudan based on a high under-5 mortality rate (96.2 deaths/1,000 live births) and high levels of undernutrition, infections, and food insecurity. Vitamin A capsules, with deworming tablets (VASD), have been delivered to preschool-aged children during national immunization days (NIDs) for the past decade. Although areas of South Sudan and certain populations continue to have low VAS coverage, when comparing national VAS coverage (reported in the last 6 months) between 2010 and August 2019, a large improvement is noted from 4% to 76%. In 2021, VAS coverage was more than 90% at the national level during 2 stand-alone distribution campaigns. Deworming coverage trends generally mimicked VAS coverage. VAS is provided to postpartum mothers who deliver at health facilities (approximately 12%–25%), but coverage data are not available.

Conclusion:

Twice-yearly VAS should remain a key lifesaving intervention to address VAD, but alternative delivery strategies will be needed. Conducting events, such as child health days, supported by promotional activities or community-based VASD distribution activities for the youngest children and those missed during campaigns, should be considered. For the long term, a hybrid approach targeting underserved areas with mass distribution events while integrating VASD into community-based programs such as quarterly screening for wasting should be tested further and gradually scaled up everywhere as this has the potential to sustainably reach all vulnerable children twice yearly.

The case for using mixed methods for designing, implementing, and disseminating evidence-based interventions for public health practice

A well-recognized gap exists between findings from public health research and their use in public health practice to improve outcomes. The World Health Organization (WHO) has identified implementation research as vital to improving the adaptation and dissemination of public health interventions into real-world settings. Implementation research encompasses multimethod evaluation approaches; 'mixed methods', the planned integration of qualitative and quantitative methods, is a key tool. We argue that mixed methods designs are crucial for design and evaluation of public health interventions, provide illustrative case studies, discuss key analytic approaches in mixed methods design, identify resources for mixed methods research and advocate for more training. On behalf of the International Network for Epidemiology in Policy (INEP), an international non-profit organization of 24 member societies that promotes the development of equitable, evidence-based health policies, we call for increased collaboration between qualitative and quantitative research teams to improve the design and evaluation of public health interventions.

Estimated effect of vitamin A supplementation on anaemia and anthropometric failure of Indian children

BACKGROUND

India has an unacceptably high burden of vitamin A deficiency (VAD) among children aged 6-59 months. To mitigate VAD and its adverse effects on child health, the Indian government runs a nationwide vitamin A supplementation (VAS) programme. However, the effect of VAS in reducing child morbidity and mortality remains inconclusive and has been debated globally. In this paper, we estimate the effect of VAS on two indicators of child nutrition-anaemia (categorized into any anaemia, and mild/moderate anaemia) and anthropometric failure (categorized into stunting, wasting, and underweight) among children aged 6-59 months.

METHODS

Using the nationally representative 2015-2016 National Family Health Survey data set from India, we set up a quasi-experimental study design and estimated household and mother fixed-effects of VAS on select types of child anaemia and anthropometric failure.

RESULTS

Findings from both the household fixed-effects and mother fixed-effects analysis showed that VAS does not influence any types of childhood anaemia and anthropometric failure in India. We discussed the findings considering existing literature and possible limitations of the study.

CONCLUSIONS

The infirm effect of Vitamin A on anaemia and anthropometric failure is probably indicative of targeted VAS intervention, as opposed to a universal VAS programme.

IMPACT

Effects of vitamin A supplementation (VAS) in treating child morbidity and mortality remain inconclusive, which calls for further rigorous studies. This study set up a quasi-experimental research design and estimated the null effect of VAS on child anaemia and childhood anthropometric failure. While the cautious interpretation of findings is urged, this study reliably supports targeted intervention of VAS, instead of the universal VAS programme. The use of nationally representative data and robust research protocol are the primary strengths of this study.

Adequate vitamin A liver stores estimated by the modified relative dose response test are positively associated with breastfeeding but not vitamin A supplementation in Senegalese urban children 9-23 months old: A comparative cross-sectional study

Vitamin A supplementation (VAS) in 6-59-month-old children is recommended but its sustainability is currently questioned. In Senegal, available data suggest that VAS should be maintained, but geographic and age-related specificities need to be addressed to better implement and target VAS programming. The objective of this comparative cross-sectional study, conducted in urban settings of Dakar, was to compare the vitamin A liver stores (VALS) assessed using the modified-relative dose response (MRDR) test between supplemented and non-supplemented 9-23 month-old children and to study their relationship with VAS. The supplemented group (n = 119) received VAS (either 100 000 UI or 200 000 UI) 2 to 6 months before evaluation while the non-supplemented group (n = 110) had not received VAS during the past 6 months. In addition to MRDR, serum retinol concentrations (SR), and biomarkers of subclinical inflammation were measured. Children's health-related data and feeding patterns were collected. Mean MRDR values (VAS: 0.030 ± 0.017, non-VAS: 0.028 ± 0.016, P = 0.389) and inflammation-adjusted SR (VAS: 1.34 ± 0.37, non-VAS: 1.3 ± 0.35, P = 0.515) of children were adequate. Low prevalence of VALS (VAS: 5.2%, non-VAS: 5.4%) and inflammation-adjusted VAD (VAS: 2.6%, non-VAS: 0.9%) were detected despite high presence of infections and inflammation. Children were mostly still being breastfed (VAS: 85.7%, non-VAS: 77.3%) and complementary feeding indicators were similar in both groups. Only breastfeeding was associated with VALS and was found to reduce by 76% at least, the odds of VAD (adjusted OR = 0.24, 95% CI: 0.07-0.8, P = 0.020). Based on MRDR values, VAS was not related to improved VALS and SR as well as VAD reduction among these children with adequate VALS. Reinforcing breastfeeding advocacy and morbidity prevention/control are essential in this setting. Scaling-back VAS in this subpopulation should be examined regarding the risk of hypervitaminosis A after an evaluation of dietary vitamin A intake sufficiency and a more quantitative assessment of VALS.

Liver is widely eaten by preschool children in the Northern Cape province of South Africa: Implications for routine vitamin A supplementation

Previous research has demonstrated a virtual absence of vitamin A deficiency and adequacy of vitamin A intake through consumption of liver in preschool children of a community in the Northern Cape province of South Africa where sheep farming is common, and liver, an exceptionally rich source of vitamin A, is frequently eaten. Only 60-75 g of liver per month is needed to meet the vitamin A requirement of preschool children. Because this may have implications for routine vitamin A supplementation, and because liver consumption for the rest of the province is unknown, the study aim was to establish the prevalence and frequency of liver intake in a provincial-wide survey. An unquantified liver-specific food frequency questionnaire, covering a period of 1 month, complemented by a 1-year recall, was administered to mothers of 2- to 5-year-old children (n = 2,864) attending primary health care facilities in all five districts and 26 subdistricts. A total of 86% of children were reported to eat liver, which was eaten in all districts by at least 80% of children. The overall median frequency of liver intake was 1.0 [25th, 75th percentiles: 0.5, 3.0] times per month and ranged from 1.0 [0.3, 2.0] to 2.0 [1.0, 4.0] for the various districts. Based on a previously reported portion size of 66 g, these results suggest vitamin A dietary adequacy in all districts and possibly also vitamin A intake exceeding the Tolerable Upper Intake Level in some children. Routine vitamin A supplementation in this province may not be necessary and should be reconsidered.

Perspective: Integration to Implementation (I-to-I) and the Micronutrient Forum-Addressing the Safety and Effectiveness of Vitamin A Supplementation

An ongoing challenge to our ability to address the role of food and nutrition in health promotion and disease prevention is how to design and implement context-specific interventions and guidance that are safe, efficacious, and avoid unintended consequences. The integration to effective implementation (I-to-I) concept is intended to address the complexities of the global health context through engagement of the continuum of stakeholders involved in the generation, translation, and implementation of evidence to public health guidance/programs. The I-to-I approach was developed under the auspices of the Micronutrient Forum and has been previously applied to the question of safety and effectiveness of interventions to prevent and treat nutritional iron deficiency. The present article applies the I-to-I approach to questions regarding the safety and utility of large-dose vitamin A supplementation programs, and presents the authors' perspective on key aspects of the topic, including coverage of the basic and applied biology of vitamin A nutrition and assessment, clinical implications, and an overview of the extant data with regard to both the justification for and utility of available intervention strategies. The article includes some practical considerations based on specific country experiences regarding the challenges of implementing vitamin A-related programs. This is followed by an overview of some challenges associated with engagement of the enabling communities that play a critical role in the implementation of these types of public health interventions. The article concludes with suggestions for potential approaches to move this important agenda forward.

Tribal Odisha Eye Disease Study Report # 6. Opportunistic screening of vitamin A deficiency through School Sight Program in tribal Odisha (India)

Purpose

To explore the possibility of vitamin A deficiency (VAD) detection through School Sight Program (SSP) in a tribal district of Odisha, India.

Methods

In a cross-sectional observational study, we tracked school children with ocular signs/symptoms of VAD to their villages. The ophthalmologist examined their under-5 siblings and other under-5 children in the village. Information pertaining to family belief and practices of food, water, sanitation, and the socioeconomic status of the family were collected.

Results

The ocular features of VAD were detected in 207 of 4801 (4.3%) examined children. This included 70 children (mean age 11 ± 2.6 years) detected in the school, 22 siblings (mean age 3.2 ± 1.2 years) of these children detected at their home, and 115 children (mean age 3 ± 1.5 years) detected in their habitat. The average family size was 5.8 ± 2.02 and the birth order of the child with VAD was 2.3 ± 1.25. Most parents were farmer, living in asbestos-roofed house, depended on public underground water, and practiced open-air defecation. The distribution of VAD in 207 children was conjunctival xerosis (X1A = 207; 100% of VAD and 4.3% of all children), Bitot's spot (X1B = 169; 81.6% of VAD and 3.5% of all children), corneal scar (XS = 3; 1.4% of VAD and 0.06% of all children), and night blindness (XN = 35; 16.9% of VAD and 0.72% of all children).

Conclusion

An opportunistic screening for detection of VAD through a SSP could be cost-effective and complement the existing strategy.

Vitamin A status in healthy women eating traditionally prepared spirulina (Dihé) in the Chad Lake area

Background

Chad Lake is a central place in a region with a high prevalence of vitamin A deficiency. Spirulina, a natural source of β-carotene, is traditionally produced and eaten as “Dihé” around Chad Lake. β-carotene spirulina has been found to have a high conversion factor to retinol. The aim of the study was to assess if the retinol status between healthy women eating spirulina Dihé daily (SPI+) and not (SPI-) in the Chad Lake area was different.

Methods

This study was observational: 88 healthy women were recruited and selected according to clinical criteria and their willingness to participate. They were divided in two groups according to their Dihé daily consumption: those who eat Dihé (SPI+; n = 35) and those who do not (SPI-; n = 35). After anthropometric and dietary assessments, blood retinol, β-carotene, retinol binding, and inflammatory/nutritional proteins were measured.

Results

The diet between groups was identical, except for β-carotene consumption, which was higher in SPI+ than in SPI- (10.8 vs. 1.8 mg/day). The serum retinol and β-carotene concentrations were significantly higher in SPI+ than in SPI- at 1.26 ± 0.36 μmol/l versus 1.03 ± 0.31 μmol/l (p = 0.008) and 0.59 ±0.37 μmol/l versus 0.46± 0.31 μmol/l (p = 0.04), respectively. Seventy-seven percent of SPI+ versus 29% of SPI- had an adequate blood retinol value (p = 0.01).

Conclusion

The results confirm that β-carotene in spirulina is an effective positive modulator of blood retinol status. Dihé is a potential natural source of β-carotene to achieve a proper vitamin A status in healthy women living near Chad Lake.

Mortality Benefits of Vitamin A Are Not Affected by Varying Frequency, Total Dose, or Duration of Supplementation

BACKGROUND

Although vitamin A supplementation reduces child mortality, it remains unclear whether dosing frequency, total dose, or duration modifies effectiveness.

OBJECTIVE

Determine whether mortality effects of vitamin A vary by dosing frequency, total dose, or duration.

METHODS

Meta-analysis of randomized controlled trials, identified by systematic review and expert opinion, utilizing relatively standard World Health Organization doses in children <5 years. Meta-regression evaluated whether mortality effects varied by dosing frequency, total dose, or supplementation duration.

RESULTS

Identified 17 trials, including 1,180,718 children, mean (standard deviation [SD]) age 31.5 (15.4) months at baseline. Supplementation frequency ranged every 3 months-every 2 years, supplementation duration 4-60 months (mean = 15.4; SD = 12.8), and total dose 134,361-2,200,000 IU (mean = 667,132 IU; SD = 540,795). Compared with control, vitamin A reduced mortality 22% (95% confidence interval [CI] = 10-32; P = 0.002). This protective effect was not modified by increasing supplementation frequency (dose/year: relative risk [RR] = 1.02; 95% CI = 0.98-1.06; P = .22), total dose (per 200,000 IU: RR = 1.02; 95% CI = 0.97-1.06; P = .31), nor supplementation duration (per year: RR = 1.06; 95% CI = 0.97-1.15; P = 0.14). Multivariate meta-regression showed similar results. Sensitivity analyses excluding 1 controversial trial (Aswathi 2013) did not alter findings.

CONCLUSION

Results confirm benefits of vitamin A supplementation in children <5 years in nations with vitamin A deficiency, without influence of frequency, total dose, or dosing duration within ranges evaluated. These findings inform design and efficiency of vitamin A supplementation policies.

Vitamin A Supplementation Programs and Country-Level Evidence of Vitamin A Deficiency

Vitamin A supplementation (VAS) programs targeted at children aged 6–59 months are implemented in many countries. By improving immune function, vitamin A (VA) reduces mortality associated with measles, diarrhea, and other illnesses. There is currently a debate regarding the relevance of VAS, but amidst the debate, researchers acknowledge that the majority of nationally-representative data on VA status is outdated. To address this data gap and contribute to the debate, we examined data from 82 countries implementing VAS programs, identified other VA programs, and assessed the recentness of national VA deficiency (VAD) data. We found that two-thirds of the countries explored either have no VAD data or data that were >10 years old (i.e., measured before 2006), which included twenty countries with VAS coverage ≥70%. Fifty-one VAS programs were implemented in parallel with at least one other VA intervention, and of these, 27 countries either had no VAD data or data collected in 2005 or earlier. To fill these gaps in VAD data, countries implementing VAS and other VA interventions should measure VA status in children at least every 10 years. At the same time, the coverage of VA interventions can also be measured. We identified three countries that have scaled down VAS, but given the lack of VA deficiency data, this would be a premature undertaking in most countries without appropriate status assessment. While the global debate about VAS is important, more attention should be directed towards individual countries where programmatic decisions are made.

Vitamin A deficiency and determinants of vitamin A status in Bangladeshi children and women: findings of a national survey

OBJECTIVE

Using data from the national micronutrients survey 2011-2012, the present study explored the status of subclinical vitamin A nutrition and the underlying determinants in the Bangladeshi population.

DESIGN

A nationwide cross-sectional study. Settings The survey covered 150 clusters; fifty in each of rural, urban and slum strata.

SUBJECTS

Three population groups: (i) pre-school age children (6-59 months; PSAC); (ii) school age children (6-14 years; SAC); and (iii) non-pregnant non-lactating women (15-49 years; NPNLW).

RESULTS

National prevalence of subclinical vitamin A deficiency was 20·5, 20·8 and 5·3 % in PSAC, SAC and NPNLW, respectively. Slum populations had higher prevalence compared with urban (PSAC: 38·1 v. 21·2 %, P0·05 for differences in β between <3 months v. 3-6 months, 6-9 months and 9-12 months).

CONCLUSIONS

Prevalence of subclinical vitamin A deficiency was high in children in Bangladesh. Intakes of animal-source foods and leafy vegetables were associated with higher and lower retinol status, respectively. Increased food diversity through animal-source foods is required.

Safety and Mortality Benefits of Delivering Vitamin A Supplementation at 6 Months of Age in Sub-Saharan Africa

Background:

Vitamin A supplementation (VAS) among children 6 to 59 months of age reduces vitamin A deficiency (VAD)-related mortality. Child health days (CHDs) only reach an estimated 16.7% of children at exactly 6 months, leaving uncovered children at risk of VAD-related mortality; similarly, VAS provided at 9 months of age with measles-containing vaccine leaves infants unprotected for 3 months.

Objective:

Using data from sub-Saharan Africa, we estimated the mortality benefits and safety of providing VAS at age 6 months, compared to delivery through CHDs and at 9 months.

Methods:

We modeled VAS-preventable mortality benefits at 6 months as a function of published VAS effect sizes, intervention coverage, and proportion of infant deaths occurring between 6 and 11 months. To evaluate safety, we modeled the effect of different VAS coverage scenarios on maximum hepatic vitamin A concentrations (HVACs).

Results:

VAS linked to a 6-month visit could reduce infant mortality by an additional 1.95 (95% confidence interval [CI]: 1.38-2.52) and 1.63 (95% CI: 1.15-2.11) percentage points compared to VAS through CHDs and at 9 months, respectively. The HVAC models indicate that VAS at 6 months is safe even in the presence of a second VAS dose 1 month later and other food-based vitamin A control strategies.

Conclusion:

Advancing the first VAS dose to 6 months should be considered in settings where VAS is currently given first at 9 months. A 6-month VAS dose should also be considered in settings where VAS is delivered through CHDs. VAS delivery at 6 months could also serve as a platform to deliver other high-impact interventions.

A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Dietary β-Carotene Bioavailability in Healthy Men

BACKGROUND

The bioavailability of β-carotene, the main dietary provitamin A carotenoid, varies among individuals. It is not known whether this variability can affect long-term β-carotene, and hence vitamin A, status.

OBJECTIVES

We hypothesized that variations in genes involved in β-carotene absorption and postprandial metabolism could at least partially explain the high interindividual variability in β-carotene bioavailability. Thus, the main objectives of this study were to identify associated single-nucleotide polymorphisms (SNPs), and to estimate whether populations with different allele frequencies at these SNPs could have different abilities to absorb provitamin A carotenoids.

METHODS

In this single-group design, 33 healthy, nonobese adult men were genotyped with the use of whole-genome microarrays. After an overnight fast, they consumed a test meal containing 100 g tomato puree providing 0.4 mg β-carotene. The postprandial plasma chylomicron β-carotene concentration was then measured at regular time intervals over 8 h. Partial least squares (PLS) regression was used to identify the best combination of SNPs in or near candidate genes (54 genes representing 2172 SNPs) that was associated with the postprandial chylomicron β-carotene response (incremental β-carotene area-under-the-curve concentration over 8 h in chylomicrons).

RESULTS

The postprandial chylomicron β-carotene response was highly variable (CV = 105%) and was positively correlated with the fasting plasma β-carotene concentration (r = 0.78; P < 0.0001). A significant (P = 6.54 × 10(-3)) multivalidated PLS regression model, which included 25 SNPs in 12 genes, explained 69% of the variance in the postprandial chylomicron β-carotene response, i.e., β-carotene bioavailability.

CONCLUSIONS

Interindividual variability in β-carotene bioavailability appears to be partially modulated by a combination of SNPs in 12 genes. This variability likely affects the long-term blood β-carotene status. A theoretic calculation of β-carotene bioavailability in 4 populations of the international HapMap project suggests that populations with different allele frequencies in these SNPs might exhibit a different ability to absorb dietary β-carotene. This trial was registered at clinicaltrials.gov as NCT02100774.