Inclusion of Micronutrient Biomarkers in National Surveys and Surveillance Systems: Barriers and Enablers

IZiNCG is pleased to share the report Inclusion of Micronutrient Biomarkers in National Surveys and Surveillance Systems: Barriers and Enablers. This work was conducted with the support of the Micronutrient Forum.

Including biomarkers of micronutrient status in existing or planned national surveys or surveillance systems would dramatically improve capacity to promote, design, monitor and evaluate micronutrient policies and programs. Ultimately, investing in better data would yield healthier populations, safer programs and cost savings. 

Yet, the availability of nationally representative micronutrient biomarker data in low- and middle income countries (LMICs) is scarce. Taking plasma/serum zinc concentrations among pre-school children as an example, only 26 LMICs have published data.

“Micronutrient deficiencies are estimated to impact a significant number of people around the world, but there remains far too little information on micronutrient status and deficiencies. More essential information and surveillance need to be gathered to make substantial progress on global targets.” 

Global Nutrition Report 2018

The objectives of this study were to identify barriers to, and enablers of, the inclusion of micronutrient biomarkers in national surveys and surveillance systems. IZiNCG conducted a series of key informant interviews with in-country and external representatives from six countries where national-level data on micronutrient status had been collected in the past five years: Cambodia, Pakistan, Malawi, Uganda, Ghana and Uzbekistan.

The most important and frequently reported barrier to inclusion of a more comprehensive panel of micronutrient biomarkers was inadequate funding to cover the analysis cost for all micronutrients considered at the planning stage. Government support and commitment was stressed as the most important enabling factor by all key informants. For the findings in full, please read the report here.

What can be done to address the barriers identified in the report, and see more countries including micronutrient biomarkers in national surveys? This project is part of a wider collaborative effort led by the Micronutrient Forum aimed at increasing the availability and utilization of high-quality data on micronutrient status at the national/sub-national levels in LMICs. Read more in this recent publication.

Last updated: June 9, 2021

Estimating national risk of zinc deficiency: proxy indicators vs. plasma/serum zinc concentrations

There is an urgent need for more and better data on the zinc status of vulnerable populations to effectively target and monitor zinc intervention programs.

Plasma/serum zinc concentration is endorsed as the best available biomarker of zinc status, particularly for assessing the risk of zinc deficiency in target population groups such as preschool-aged children and women of reproductive age. Given the scarcity of nationally representative PZC data, global estimates for the risk of zinc deficiency have been based on two proxy measures:

• the amount of absorbable zinc in the national food supply, and

• the prevalence of stunting among children under five.

The risk of zinc deficiency is considered to be elevated and a likely public health problem when the prevalence of inadequate absorbable zinc intakes is >25% and if stunting rates are >20%.

National risk of zinc deficiency based on the prevalence of childhood stunting and the estimated prevalence of inadequate zinc intake (Wessells & Brown, 2012)

Wessells & Brown estimated the global prevalence of zinc deficiency:

• Based on the Food and Agriculture Organization of the United Nations’ (FAO) Food Balance Sheets, at least 17% of the world’s population is at risk of inadequate zinc intake.

• In 2011, 84 low-and middle-income countries (LMICs) with available data had a stunting prevalence >20% among children <5 years of age. Furthermore, 32 of these countries were identified as high risk based on both dietary intake and stunting.

However, comparisons with data from national surveys that have measured plasma or serum zinc concentration show that intake based on food balance sheets underestimate the risk of zinc deficiency. As seen in the map below, the prevalence of low plasma/serum zinc concentrations in young children was >20% in the majority of the surveys.

Percentage of pre-school children with low plasma or serum zinc concentrations. Map generated from data in the World Health Organization’s Vitamin and Mineral Nutrition Information System Micronutrients Database.

Read more:

• IZiNCG Technical Brief no. 9 - The value of measuring plasma or serum zinc concentrations in national surveys

• IZiNCG Technical Document no. 1 - Assessment of the Risk of Zinc deficiency in populations and options for its control

• IZiNCG Practical Tips: Collecting Blood in the Field for Assessment of Plasma or Serum Zinc Concentration

External links:

• World Health Organization’s Vitamin and Mineral Nutrition Information System Micronutrients Database

• OpeN-Global - Open access knowledge hub of Nutritional biomarkers for Global Health

Countries with population-level data on plasma/serum zinc concentrations

IZiNCG keeps a global inventory of recently completed and upcoming national nutrition surveys in low- and middle income countries where plasma/serum zinc concentrations have been assessed. Countries for which published reports are available are listed below.

In 2018, plasma/serum zinc was incorporated into WHO’s Micronutrient Database, which enables data visualization. Two publications have summarized available nationally-representative data on plasma/serum zinc concentrations: Hess 2017 and Gupta et al 2020.

Last updated: 10 November 2022

Afghanistan — National Nutrition Survey Afghanistan (2013) Survey Report
Azerbaijan — Nutrition Survey 2013 
Bangladesh — National Micronutrients Status Survey 2011-12 – Final Report
Cambodia — The High Prevalence of Anemia in Cambodian Children and Women Cannot Be Satisfactorily Explained by Nutritional Deficiencies or Hemoglobin Disorders
Cameroon — Stunting Prevalence, Plasma Zinc Concentrations, and Dietary Zinc Intakes in a Nationally Representative Sample Suggest a High Risk of Zinc Deficiency among Women and Young Children in Cameroon
China — survey data (2013) for children 36-72 months available in National Risk of Zinc Deficiency as Estimated by National Surveys
Colombia — Factores asociados a la deficiencia de zinc en niños colombianos; resultados de la Encuesta Nacional de Salud 2010; estudio transversal 
Costa Rica —Encuesta Nacional de Nutrición 2008-2009
Equador — Encuesta Nacional de Salud y Nutrición (ENSANUT-ECU) 2011-2013
Ethiopia — Ethiopian National Micronutrient Survey Report, September 2016
Fiji —  2014 – 2015 National Nutrition Survey (available on request)
Guatemala — Encuesta Nacional de Micronutrientes 2009-2010; SIVESNU 2016
India — Comprehensive National Nutrition Survey: 2016-2018; Prevalence of low serum zinc concentrations in Indian children and adolescents: findings from the Comprehensive National Nutrition Survey 2016–18
Iran — Second National Integrated Micronutrient Survey in Iran: Study Design and Preliminary Findings
Jordan  — Jordan National Micronutrient and Nutrition Survey 2019
Kenya —  The Kenya National Micronutrient Survey 2011
Malawi — Malawi Micronutrient Survey Key Indicators Report 2015-16
Maldives — Project Report National Micronutrient Survey 2007 Republic of Maldives
Mexico — Anemia and iron, zinc, copper and magnesium deficiency in Mexican adolescents: National Health and Nutrition Survey 2006 ; Prevalence of Zinc Deficiency in Mexican Children and Women of Childbearing Age (abstract);  Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years ; Iron, zinc, copper and magnesium deficiencies in Mexican adults from the National Health and Nutrition Survey 2006
Myanmar —Myanmar Micronutrient and Food Consumption Survey MMFCS (2017-2018) Interim Report (Feb 2019)
Nepal — Nepal National Micronutrient Status Survey
Nigeria — Nigeria Food Consumption and Nutrition Survey 2001-2003: Summary
Pakistan — Pakistan National Nutrition Survey 2018 - key findings report
Philippines — 8th National Nutrition Survey: Philippine Nutrition Facts and Figures 2013: Biochemical Survey
Senegal — Statut en Zinc des Enfants Senegalais et Evaluation de L’Utilisation de la Concentration Plasmatique en Zinc pour Tester L’Impact des Programmes de Fortification ; Adjusting Plasma Concentrations of Ferritin, Retinol, and Zinc Affect the Prevalence of Micronutrient Deficiencies in Children but Not in Women (abstract)
Somalia  — Somalia micronutrient survey 2019 (capillary blood zinc concentrations)
South Africa — National Food Consumption Survey-Fortification Baseline (NFCS-FB-I): South Africa, 2005
Sri Lanka — National Nutrition and Micronutrient Survey – Part II: Iron, Zinc and Calcium Deficiency Among Children Aged 6-59 Months
Timor Leste — Timor-Leste Food and Nutrition Survey 2013- Final Report
Vietnam — Micronutrient Deficits Are Still Public Health Issues among Women and Young Children in Vietnam +new data coming