Mandatory large-scale food fortification programmes can reduce the estimated prevalence of inadequate zinc intake by up to 50% globally

A new publication in Nature Food shows that if high-quality mandatory large-scale food fortification programmes that include zinc as a fortificant was implemented in all countries where zinc deficiency is a potential public health problem, the estimated prevalence of inadequate zinc intake could be reduced by up to 50% globally.

Large-scale food fortification (LSFF) reduces the prevalence of zinc deficiency. By using food balance sheet data from the Food and Agriculture Organization of the United Nations, we estimated that 15% of the global population (1.13 billion individuals) have inadequate zinc intake, accounting for LSFF programmes as currently implemented.

We asked what the impact of LSFF with zinc could be if investments were made to introduce mandatory LSFF programmes, to expand LSFF programmes to include zinc, to align zinc standards with current international guidelines, and to improve industry compliance.

We found that a substantial impact could be achieved. The implementation of high-quality mandatory LSFF of cereal grains (that is, wheat flour, maize flour and rice) in 40 countries where zinc deficiency is considered a public health problem could increase the availability of zinc in the national food supply, thus reducing the estimated global prevalence of inadequate zinc intake by up to 50%. As one would expect, fortification opportunities differ widely among countries. This is due to differences such as the percentage of the grains industrially fortified, and the daily per capita availability of the fortification vehicles; the country-specific estimated relative reductions ranged from 15% to 96%.

These findings can be used to preliminarily inform country- and context-specific LSFF programmes for cereal grains in individual countries. As with all nutrition interventions, LSFF is not a stand-alone strategy to improve dietary zinc intake; instead, it should be combined with other interventions to meet the needs of all populations at risk of zinc deficiency, including the most vulnerable. Nevertheless, investments to strengthen and expand LSFF programmes in which zinc is included as a fortificant hold great potential to enhance dietary zinc intake and improve the population zinc status in countries where zinc deficiency is considered a public health problem.

Upcoming webinar: Large-scale food fortification – an underutilized strategy for addressing zinc deficiency

Date: December 5

Time: 12 noon EDT | 5 pm GMT | 8 pm EAT

Over the past four years, IZiNCG’s Zinc Fortification Task Force has generated evidence and advocacy materials on large-scale food fortification (LSFF) with zinc. This webinar will showcase work undertaken by the Task Force, and discuss country experiences and actions.

Zinc is an essential nutrient for immune function, child health and development, and reproductive health. Based on available data, zinc deficiency is estimated to be a public health problem in 40 countries, concentrated primarily in sub-Saharan Africa and South Asia

LSFF is one of the most scalable, sustainable, and cost-effective tools available to reduce micronutrient deficiencies and improve nutrition worldwide. Recent publications have demonstrated that LSFF with zinc is effective, safe and cost-effective. However, at present, LSFF with zinc is an underutilized strategy for addressing zinc deficiency in countries where zinc deficiency is a public health problem.

Join us for presentations on the global state of zinc deficiency, the evidence behind zinc fortification as a strategy to address zinc deficiency, the current zinc fortification landscape, the potential impact of scaling up food fortification with zinc, and priority actions countries can take. The webinar will conclude with a panel discussion about country experiences. Register here.

Moderator
Dr Mduduzi Mbuya | Director, Knowledge Leadership, Global Alliance for Improved Nutrition

Speakers and panelists
Dr Christine McDonald | Director of IZiNCG and Associate Professor, University of California, San Francisco
Dr Mari Skar Manger | Deputy Director of IZiNCG, University of California, San Francisco
Dr Ryan Wessells | Associate Project Scientist, University of California, Davis
Mr Frederick Grant | Senior Program Officer, Nutrition, Bill & Melinda Gates Foundation Ethiopia
Dr Ndèye Fatou Ndiaye | Coordinator of Senegalese Committee for Food Fortification (COSFAM), Ministry of Industry and Industrial Development, Government of Senegal
Mr Alex Marco Ongla Ndjebayi | Project Coordinator, Helen Keller International Cameroon

This webinar is kindly supported by the International Zinc Association and kindly hosted by the Global Alliance for Improved Nutrition. Everyone who registers will receive a recording of the webinar.

New video about zinc fortification!

IZiNCG is pleased to share our new animated short produced in collaboration with the International Zinc Association. The video is only 2 minutes long – enjoy!

Fortification as a strategy to reduce zinc deficiency.

Zinc fortification country briefs: Honduras, Burkina Faso and Senegal

Zinc fortification reduces the prevalence of zinc deficiency and may improve associated health outcomes. Which actions should governments and supporting partners take to address zinc deficiency through fortification?

A July 2021 analysis conducted by IZiNCG identified 35 countries where zinc deficiency is a national public health issue. Honduras, Burkina Faso and Senegal are among these countries, but their existing large-scale food fortification programs do not include zinc. Adding zinc to these existing mandatory fortification programs would be a relatively low-cost, high-impact intervention to reduce their national prevalence of zinc deficiency. 

These country briefs provide the rationale for zinc fortification, describe where the selected countries stand with regards to zinc deficiency and food fortification, and outline key actions government and supporting partners can take to address zinc deficiency through zinc fortification.

Honduras

Burkina Faso

Senegal

Call to Action: Addressing zinc deficiency through zinc fortification

IZiNCG’s Zinc Fortification Task Force is pleased to share this Call to Action to close the global zinc fortification gap.

Large-scale food fortification (LSFF) is one of the most effective interventions for improving micronutrient status. We have recently published a systematic review and meta-analysis which showed that zinc fortification can reduce the prevalence of zinc deficiency.

This advocacy brief presents the LSFF situation in countries where zinc deficiency is a public health issue, and outlines priority actions these countries should take pertaining to food fortification. Among these countries are 11 countries where zinc fortification can have a significant and immediate impact because a mandatory fortification program already exists, but it does not include zinc.

The members of our Zinc Fortification Task Force represent the Food Fortification Initiative, the Global Alliance for Improved Nutrition, Nutrition International, and the IZiNCG Steering Committee.

Enablers and barriers of zinc fortification; experience from 10 low- and middle-income countries

The first publication from IZiNCG’s Zinc Fortification Task Force, Enablers and Barriers of Zinc Fortification; Experience from 10 Low- and Middle-Income Countries with Mandatory Large-Scale Food Fortification, is now available in Nutrients.

Food fortification presents an opportunity for enhancing zinc intakes. Despite data suggesting zinc deficiency as being a potential public health problem, only 29 out of 72 low- and middle-income countries with mandatory fortification programs for cereal grains include zinc as a mandatory fortificant.

To guide policy decisions, we investigated the factors enabling and impeding the inclusion of zinc as a fortificant by conducting a series of in-depth interviews with key informants from 10 countries. We learnt that the decision to include zinc was strongly influenced by guidance from international development partners. Enabling factors included the assessment of zinc deficiency, mandatory regional food fortification standards which included zinc, the World Health Organization (WHO) guidelines for zinc fortification, and the low cost of the zinc compound commonly used. Barriers included the absence of zinc from regional fortification standards, limited available data on the efficacy and effectiveness of zinc fortification, and the absence of national objectives related to the prevention of zinc deficiency.

Systematic review coming soon

More evidence about the impact of zinc fortification is available now compared with when many of the countries interviewed the planning of their zinc fortification programs. We have conducted a review of efficacy and effectiveness studies to ascertain the effect of zinc fortification - alone or with multiple micronutrients - on a range of health outcomes. The review has been accepted for publication in Advances of Nutrition.

IZiNCG’s Zinc Fortification Task Force

The objective of Phase 1 of the Task Force has been to assess the efficacy and effectiveness of zinc fortification interventions, and to identify opportunities to enhance impact. We are now moving into Phase 2 - watch this space. Our members represent the Food Fortification Initiative, the Global Alliance for Improved Nutrition, Nutrition International, and the Global Fortification Data Exchange.

Read more about strategies for promoting zinc nutrition here.

Fortified Rice for School Children in Cambodia. The FORISCA project.

In their guest blog for IZiNCG, Khov Kuong (DFPTQ, Fisheries Administration, Ministry of Agriculture, Forestry and Fisheries) and Frank Wieringa (the French National Research Institute for Sustainable Development (IRD)) share the findings from the newly published FORSICA project.

Zinc deficiency is highly prevalent in Cambodia. The 2014 Micronutrient Survey in Cambodia found that >60% of the women of reproductive age and under-five children had plasma zinc concentrations <9.9 mmol/L, indicative of zinc deficiency [1]. Other indicators for zinc deficiency, such as stunting prevalence, are highly prevalent too, which the latest Demographic Health Survey (2014) reporting 1 in 3 children being stunted [2]. Although there are few data available, it is likely that zinc status is poor in other age groups in Cambodia, such as in school-aged children. 

To improve zinc status of the Cambodian population, the use of zinc-fortified rice is a tempting solution. The consumption of rice in Cambodia is very high, with >60% of daily energy intake coming from rice. Also, zinc-fortified rice is very stable, without zinc being lost over time, or when using different rice cooking techniques [3]. And rice fortified with zinc, iron, and B-vitamins was found to be highly acceptable in Cambodia [4]. Before the start of the FORISCA ((Fortified Rice for School Children in Cambodia) project, we tested the organoleptic qualities of different types of fortified rice on mothers and school teachers. Interestingly, over 80% of the mothers were capable of picking out correctly the fortified rice out of a sample of 3 plates of rice. But the fortified rice scored high on different aspects of organoleptic qualities, such as smell and taste. 

As the United Nations World Food Program (WFP) in Cambodia was exploring possibilities to improve nutritional status of school children in Cambodia through use of fortified foods in school meal programs, we took the opportunity to test the impact of introducing fortified rice on micronutrient status, morbidity and cognitive development in school children. Together with the US-based NGO PATH, and co-funded by the United States Department of Agriculture (USDA), WFP-DSM consortium and IRD, we recruited almost 10,000 school children within the FORISCA project. The FORISCA project was developed together with the Government of Cambodia’s Ministry of Education, Youth and Sports, The Ministry of Agriculture, Forestry and Fisheries and the National Fortification Board. The aim of the project was two-fold. First, to test whether a daily breakfast with multiple-micronutrient fortified rice could reduce anemia prevalence, improve micronutrient status and improve functional outcomes such as cognitive development and incidence of infectious diseases. The second aim was to test whether different types of fortified rice (i.e. cold extruded vs hot extruded) had different efficacy in improving micronutrient status. For this aim, 3 different types of fortified rice where tested, with different micronutrient composition and different fabrication techniques. 

The micronutrient content of the different fortified rice groups tested in the FORISCA project, per 100 g of uncooked blended rice.

Within the FORISCA project, school children were given a standard breakfast, 6 days per week, for 6 months. The breakfast consisted of rice (~100 g dry rice per child per day), with a sauce of tomatoes, oil (fortified with vitamin A) and fish (~5 g per child per day). Breakfast was prepared every morning in the school kitchen, and meals were distributed over the classes. 

Schools were allocated to receive either normal rice, or one of the 3 different types of fortified rice tested. Children would receive their breakfast at 7 in the morning, and class would start thereafter. Children were assessed for anthropometry, cognitive development and micronutrient status at baseline, midline (after 3 months) and at endline. 

Baseline micronutrient status confirmed our suspicion that zinc status was poor in school-aged children in Cambodia, with >80% of the school children having low plasma zinc concentrations [5]. Severe zinc deficiency, defined as a plasma zinc concentration <7.6 mmol/L) was present in ~50% of the school children. Six-month consumption of rice fortified with zinc significantly reduced the prevalence of zinc deficiency in the children, with the fortified rice with the highest zinc content, (Nutri-Rice) having the greatest reduction. At endline of the study, the prevalence of zinc deficiency and severe deficiency had not changed in the group receiving ordinary rice, and remained very high at 93% and 54% respectively. In contrast, in the Nutri-Rice group, the prevalence of zinc deficiency and severe zinc deficiency had decreased to 66% and 25% respectively. In the Ultra-Rice Improved group of school children, which was the fortified rice with the lowest fortification level of zinc, the prevalence of zinc deficiency and severe zinc deficiency was reduced too as compared to the placebo group, but to a lesser extent than in the Nutri-Rice group (to 83% and 37% respectively). 

We calculated that the zinc fortified rice contributed between 29% (Ultra-Rice improved) and 53% (Nutri-Rice) of the Recommended Daily Allowance (RDA) of the school children over the 6 month intervention period. Clearly, the higher zinc content of the Nutri-Rice contributed to the greater impact on zinc status. But even with ~50% of the RDA covered by the fortified breakfast, 25% of the children remained severely zinc deficient. Given the very high prevalence of zinc deficiency in this population, the amount of zinc in the fortified rice could easily be doubled, to cover 100% of the RDA. Vitamin A status was improved also in the children who received rice fortified with vitamin A, with children in the Ultra-Rice improved and Nutri-Rice groups having a risk for marginal vitamin A status that was 1/5 and 1/4 respectively of children receiving normal rice [6].

The prevalence of anemia in the school children was lower than expected, at 16% [6]. Surprisingly, the prevalence of iron deficiency was very low, with <2% of the children having iron deficiency, and hence, the fortified rice had little impact on anemia prevalence or on improving iron status. Sub-clinical inflammation also played a role here, as in children without inflammation, there was a tendency towards higher haemoglobin concentrations in all the groups receiving fortified rice. 

Another surprising outcome of the FORISCA project was the increase in hookworm infection in the children receiving fortified rice. At baseline, all children were dewormed. However, after 6 months, up to 30% of the children were re-infected, and the re-infection rate was higher in the children receiving fortified rice than in the children receiving normal rice[7]. The re-infection rate was highest in the children receiving the fortified rice with the highest iron content, making us believe that the iron in the fortified rice played a role in enabling the re-establishment of the hookworm infection. Also, as hookworm re-infection rate tended to be higher in the cold-extruded fortified rice groups, bioavailability of iron might have been different between the cold- and hot-extruded rice varieties. 

Finally, despite the differences in zinc content of the 3 groups of fortified rice, both types of extruded fortified rice (cold vs hot extruded rice) were effective in improving zinc status and therefore production method appears not to be an important factor in determining the impact on zinc status of fortified rice. 

The WFP in Cambodia is currently assessing the expanded use of fortified rice in the school meal program, and the aim is to have a rice fortified breakfast for all the children participating in the school meal program, meaning that almost 250,000 children will hopefully receive a fortified rice meal soon.

REFERENCES

1.         Wieringa FT, Dahl M, Chamnan C, Poirot E, Kuong K, Sophonneary P, Sinuon M, Greuffeille V, Hong R, Berger J, et al: The High Prevalence of Anemia in Cambodian Children and Women Cannot Be Satisfactorily Explained by Nutritional Deficiencies or Hemoglobin Disorders. Nutrients 2016, 8.

2.         Cambodia Demographic and Health Survey 2014. [https://dhsprogram.com/pubs/pdf/FR312/FR312.pdf]

3.         Kuong K, Laillou A, Chea C, Chamnan C, Berger J, Wieringa FT: Stability of Vitamin A, Iron and Zinc in Fortified Rice during Storage and Its Impact on Future National Standards and Programs-Case Study in Cambodia. Nutrients 2016, 8.

4.         Khanh Van T, Burja K, Thuy Nga T, Kong K, Berger J, Gardner M, Dijkhuizen MA, Hop le T, Tuyen le D, Wieringa FT: Organoleptic qualities and acceptability of fortified rice in two Southeast Asian countries. Ann N Y Acad Sci 2014, 1324:48-54.

5.         Kuong K, Tor P, Perignon M, Fiorentino M, Chamnan C, Berger J, Burja K, Dijkhuizen MA, Parker M, Roos N, Wieringa FT: Multi-Micronutrient Fortified Rice Improved Serum Zinc and Folate Concentrations of Cambodian School Children. A Double-Blinded Cluster-Randomized Controlled Trial. Nutrients 2019, 11.

6.         Perignon M, Fiorentino M, Kuong K, Dijkhuizen M, Burja K, Parker M, Chamnan C, Berger J, Wieringa FT: Impact of Multi-Micronutrient Fortified Rice on Hemoglobin, Iron and Vitamin A Status of Cambodian Schoolchildren: a Double-Blind Cluster-Randomized Controlled Trial.Nutrients 2016, 8:doi:10.3390/nu8010029.

7.         de Gier B, Campos Ponce M, Perignon M, Fiorentino M, Khov K, Chamnan C, de Boer MR, Parker ME, Burja K, Dijkhuizen MA, et al: Micronutrient-Fortified Rice Can Increase Hookworm Infection Risk: A Cluster Randomized Trial. PLoS One 2016, 11:e0145351.

IZiNCG Symposium at Micronutrient Forum 5th Global Conference March 2020

The Micronutrient Forum 5th Annual Conference will be held in Bangkok from March 23rd to 27th 2020. The theme is Building new Evidence and Alliances for Improving Nutrition, and our colleagues at the Micronutrient Forum are promising their best conference yet!

If you are going to Bangkok, please mark Wednesday March 25th from 12.30 to 2pm in your calendar now for IZiNCG’s Symposium titled Advancing Efforts to Improve Zinc Nutrition Globally. We will present on recent developments and opportunities for action in assessment of zinc status, advances in the delivery of additional zinc to vulnerable populations, and progress in the use of therapeutic zinc as part of diarrhoea treatment. One of the presentations will share preliminary findings from the Zinc in Powders Trial, where data collection is on track to finish by January 30, 2020.

See you there?

Update: The Micronutrient Forum 5th Annual Conference has been postponed and will now take place between November 8-13, 2020.

IZiNCG Awarded New Grant from the Bill & Melinda Gates Foundation to Evaluate the Nutritional Impact of Multiply-Fortified Salt Among Women of Reproductive Age in India

IZiNCG is pleased to announce the receipt of a grant from the Bill & Melinda Gates Foundation to evaluate the nutritional impact of quintuply-fortified salt vs. standard iodised salt for the improvement of micronutrient status among non-pregnant women of reproductive age in Punjab, India. This project is a collaborative effort primarily between IZiNCG, the Postgraduate Institute of Medical Education and Research (PGIMER), and the Haryana State Government.

Why women of reproductive age?

Women of reproductive age (WRA) and young children are particularly vulnerable to multiple micronutrient deficiencies, and prevalences of deficiency remain unacceptably high in India. The 2015-2016 National Family Health Survey revealed that over half of non-pregnant WRA in India are anaemic. A recent survey of 866 WRA in Haryana demonstrated the co-occurrence of multiple micronutrient deficiencies: 75% of WRA had iron deficiency, 80% had folate insufficiency, and 82% had vitamin B12 deficiency (unpublished observations).  Although plasma zinc concentrations were not assessed, the high prevalence of stunting and the low level of absorbable zinc in the national food supply are suggestive of a high prevalence of zinc deficiency.

Why zinc, iron, vitamin B12 and folate?

Zinc, iron, vitamin B12, and folate are critically important for several biological processes related to a healthy pregnancy and the optimal growth and development of the foetus and offspring. Thus, deficiencies in these micronutrients are associated with several adverse health outcomes ranging from preterm and small-for-gestational-age births, neural tube defects, stunting and childhood diarrhoea.  These health problems are widespread in India where more than 3.5 million infants are born preterm each year, nearly 10% of children under 5 have had diarrhoea in the previous 2 weeks, and 38% of children under 5 are stunted. A recent analysis estimated that the prevalence of neural tube defects in South Asia is 32 per 10,000 live births. Clearly, there is an urgent need to improve the micronutrient status of Indian WRA and their children.

Photo credit: World Bank Photo Collection

Salt as a novel vehicle for multiple micronutrient fortification

Micronutrient fortification of a staple food or condiment can be an effective strategy for improving the micronutrient status of a population, as the approach is cost-effective, utilises existing delivery systems, can deliver multiple micronutrients simultaneously, and does not require behaviour change by the population.

Salt is an attractive vehicle for multiple micronutrient fortification in India, as it is universally consumed in fairly consistent amounts. India already has excellent coverage of iodized salt and has recently scaled up the distribution of salt fortified with iodine and iron (double-fortified salt).

Extensive research conducted in various settings has shown that double-fortified salt significantly improves iron status in nutritionally vulnerable groups. With new technology developed by the University of Toronto, it is now possible to fortify salt with multiple micronutrients, including zinc, vitamin B12, and folic acid, in addition to iron and iodine.

While salt fortified with encapsulated ferrous fumarate is already being produced at scale and extensively consumed by large populations in India, the planned study proposes to conduct a head-to-head comparison with ferric pyrophosphate likely in combination with citric acid and trisodium citrate (to enhance iron absorption) in an encapsulated medium that is under development and test whether sensory qualities could be improved further.

Plan for the study 

The study will be conducted in two phases. Phase 1 will include formative research involving a dietary assessment to ascertain habitual salt intake and dietary intake of micronutrients; qualitative research to understand salt procurement, storage, and utilization practices; as well as sensory and acceptability testing of the quintuply-fortified salts.

Phase 2 will be a double-blind, randomised controlled efficacy trial where 750 women of reproductive age will be randomised to 1 of 3 groups: 1) quintuply fortified salt with iron in the form of encapsulated ferrous fumarate; 2) quintuply fortified salt with iron in the form of ferric pyrophosphate; and 3) iodised salt. In brief, participating women will be provided with the assigned study salt on a monthly basis for 12 months and blood samples will be taken at baseline, 6 months, and 12 months. The primary outcome will be micronutrient status as measured by the change in biomarkers of zinc, iron, folate, vitamin B12 and iodine status. Secondary outcomes to be assessed include DNA damage, essential fatty metabolism and cognition. 

If proven efficacious, MFS has the potential not only to improve the micronutrient status of WRA, but also lead to improved perinatal outcomes, and better micronutrient status in their offspring. Together with our collaborators, IZiNCG is excited to initiate this study!

Collaborators: PGIMER, Haryana State Government, SWACH Foundation, WHO Southeast Asia, the University of Toronto, Tata Trusts/ The India Nutrition Initiative, ETH Zürich, JVS Foods, St. John’s Research Institute, University of Colorado Denver, University of California Davis, Eurofins, University of Otago, University of Nottingham, VitMin laboratory.

Last edited 24.03.2020.

Read more:

Strategies for promoting zinc nutrition

Zinc supplementation during pregnancy

Zinc Fortification Task Force 

Case study: Addressing Zinc Deficiency Through Wheat Flour Fortification in Cameroon

As part of a series of case-studies on population-level zinc interventions, Ann Tarini (Independent Consultant), Ismael Teta, Alex Ndjebayi and Jules Guintang Assiene (Helen Keller International, Cameroon) and Reina Engle-Stone (UC Davis) have summarised the Cameroon experience of implementing wheat flour fortification to address zinc deficiency in a new IZiNCG brief.

Food fortification is one of three main strategies to address zinc deficiency in a population. This six page brief covers key program milestones, the rationale for wheat flour fortification, early program impact, a commentary on sustainability, and key lessons learned.

But perhaps most importantly, it highlights the power of data. Prior to 2009, no information was available on the status of zinc and several other micronutrients in Cameroon. In 2009, the Ministry of Public Health conducted a National Micronutrient Survey; the availability of data on plasma zinc concentration enabled the identification of zinc deficiency as a public health problem, and dietary intake data helped identify possible fortification vehicles along with their potential impact. The measurement of plasma zinc concentrations in the two major urban centers in 2012 enabled inference about program impact. And without monitoring data, it would not have been possible to identify and address the faltering of the program in 2016.

We hope Cameroon’s experience can provide inspiration and guidance to other countries considering zinc fortification.

Related:

IZiNCG Research Projects: Zinc Fortification Task Force

IZiNCG Technical Brief no. 4: Zinc Fortification

IZiNCG Technical Document no. 2

Zinc Fortification Task Force initiates efforts to enhance the impact of zinc fortification interventions

Why a Zinc Fortification Task Force?

Fortification of staple foods and/or condiments with zinc appears to be a promising strategy for improving zinc status at the population level in low- and middle-income countries because of its relatively low cost and long-term sustainability. The motivation for establishing a Zinc Fortification Task Force is to progress IZiNCG’s position and recommendations related to zinc fortification, taking into account recent evidence, existing global guidelines, and the fact that mandatory zinc fortification is in place in more than 30 countries. The Task Force harnesses the perspectives of the Food Fortification Initiative, the Global Alliance for Improved Nutrition and Helen Keller International together with IZiNCG.

IZiNCG’s current stance on zinc fortification 

A review in IZiNCG’s 2009 Technical Document no. 2 summarised evidence showing that fortifying staple foods with zinc increases total daily zinc absorption, does not adversely affect the absorption of other minerals, is not associated with adverse effects and is a relatively low-cost intervention (1). Therefore, IZiNCG’s recommendation following this review was that countries should consider including zinc in mass and targeted fortification programs in populations at high risk of zinc deficiency. However, the review also pointed to the paucity of evidence on the efficacy and effectiveness of fortification programs, and that only a few studies had found a positive impact on plasma/serum zinc or functional indicators of zinc status.

Recent reviews

A 2016 Cochrane review of zinc fortification concluded the same: given the relatively small number of trials and participants, further investigation of the effects of zinc fortification was needed (2). However, the Cochrane review excluded many studies on the basis that zinc was not the only nutrient which differed between intervention and control groups, despite plasma/serum zinc being measured as an outcome. While such comparisons may be useful from an epidemiological perspective, they may not fully capture the real-world context.  For example, 34 countries have mandatory zinc fortification in place, with zinc being part of a premix with several other micronutrients. In a very recent review of large-scale food fortification on vitamin A, iodine, iron and folic acid status and health outcomes, this “real-world impact” was at the centre (3). However, this latter review excluded trials with less than 1000 participants, which would be too limiting in the case of available publications on zinc fortification.

Planned work of the taskforce 

The overarching goal of the task force is to assess the efficacy and effectiveness of zinc fortification interventions, and to identify opportunities to enhance impact. The first activity is to produce an update to the previous zinc fortification systematic reviews, summarising the additional evidence now available on zinc fortification. In addition to determining the impact of zinc fortification on zinc-related biochemical and functional outcomes, the review will attempt to answer the following other questions: 

• What is the adequate dosage and duration of exposure required to show an effect?

• What proportion reduction in zinc deficiency can we expect to see as a result of zinc fortification, and which groups may require additional/complementary interventions? 

• Which indicators should be recommended for evaluating zinc fortification programs?

• What do we know about novel/alternative vehicles for zinc fortification? 

In parallel, the Zinc Fortification Task Force also wants to capture the lessons learnt and identify knowledge and resource gaps in countries with existing national zinc fortification programs. Which evidence did they act on? Which barriers are they facing? Likewise, the Task Force plans to explore the perspectives of countries with a high burden of zinc deficiency without zinc fortification in place, and the feasibility of zinc fortification as a successful strategy in such settings. 

We hope that the results from the activities in this first phase of the Zinc Fortification Task Force will be available by July 2020, and that this effort will help inform renewed global commitments to food fortification. 

References

1. Hess SY, Brown KH. Impact of zinc fortification on zinc nutrition. Food Nutr Bull. 2009 Mar;30(1 Suppl):S79-107. 

2. Shah D, Sachdev HS, Gera T, De-Regil LM, Peña-Rosas JP. Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population. Cochrane Database Syst Rev. 2016 Jun 9;(6):CD010697.

3. Keats EC, Neufeld LM, Garrett GS, Mbuya MNN, Bhutta ZA. Improved micronutrient status and health outcomes in low- and middle-income countries following large-scale fortification: evidence from a systematic review and meta-analysis. Am J Clin Nutr. 2019 Jun 1;109(6):1696-1708.

Read more about strategies for promoting zinc nutrition here.