Holiday Greetings!

Holiday Greetings!

It is time to look back at what has been achieved in 2018, and to thank all our supporters and contributors. We are looking forward to engaging with you in 2019!

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New IZiNCG technical brief: The value of measuring plasma or serum zinc concentrations in national surveys

New IZiNCG technical brief: The value of measuring plasma or serum zinc concentrations in national surveys

“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

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. IZiNCG’s new Technical Brief no. 9 outlines the value of measuring plasma/serum zinc concentration in national nutrition or health-related surveys. If a population is considered at high-risk of zinc deficiency based on inadequacy of zinc in the food supply or a high prevalence of child stunting, IZiNCG recommends that plasma/serum zinc be measured in vulnerable groups.

We are pleased that plasma/serum zinc data are now included in the World Health Organization’s Vitamin and Mineral Nutrition Information System Micronutrient Database and have partnered with the Micronutrient Forum to initiate a working group to promote the inclusion of micronutrient biomarkers in large-scale surveys. 

For more information about the measurement of plasma or serum zinc concentrations, refer to previous IZiNCG Technical Briefs and Technical Documents, and the Biomarkers of Nutrition for Development (BOND) - Zinc Review.

Recent publication: A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc

Recent publication: A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc

Zinc deficiency limits infant growth and increases susceptibility to infections, which further compromises growth. Zinc supplementation improves the growth of zinc-deficient stunted infants, but the amount, frequency, and duration of zinc supplementation required to restore growth in an individual child is unknown. A dynamic model of zinc metabolism that predicts changes in weight and length of zinc-deficient, stunted infants with dietary zinc would be useful to define effective zinc supplementation regimens.

A model of zinc metabolism was developed using data on zinc kinetics, tissue zinc, and growth requirements for healthy 9 month old infants. The model suggests that frequent, smaller doses (5–10 mg Zn/d) are more effective for increasing growth in stunted, zinc-deficient 9-mo-old infants than are larger, less-frequent doses.

In the future, the model predictions of zinc supplementation need to be evaluated in homogenous groups of stunted infants with respect to age, sex, and zinc status. That information will improve predicted amounts of supplemental zinc, and it will identify the population subgroups (e.g., infants with plasma zinc and length-for-age z score below defined thresholds) most likely to respond to zinc supplementation.

The publication can be found here.

Study in progress: Reference methods for biological sample preparation and zinc analysis

Study in progress: Reference methods for biological sample preparation and zinc analysis

The accurate determination of the prevalence of zinc deficiency is essential for effective design, targeting, and evaluation of interventions. Hence, methodological knowledge gaps are important to understand and address.

The concentration of zinc in biological samples, such as plasma, serum, hair, or urine, varies considerably between populations. While part of this variation is attributable to differences in diet or inflammation – i.e. what we want to measure – part may also be due to the different methods and equipment used to process and analyze the samples. 

Instruments commonly used for zinc analysis include atomic absorption spectrometry (AAS), inductively couple plasma optical (atomic) emission spectrometry (ICP-OES / ICP-AES), and ICP mass spectrometry (ICP-MS). 

IZiNCG has earlier published reference methods for collecting plasma and serum for zinc analysis, but reference methods for sample preparation and zinc analysis have not yet been developed. 

The goals of this project are to:

a)    Establish a set of reference methods for zinc analysis, applicable to new or established laboratories using each major type of instrument; and 

b)    Develop reference data that document analytical accuracy and precision among different instruments and different types of samples under ideal conditions at multiple sites. 

The results, anticipated in January 2019, will be communicated as an IZiNCG technical brief following publication in a peer-reviewed scientific journal.

Participating labs:

AAS

University of Colorado Denver, USA

ETH Zurich, Switzerland

Aga Khan University, Pakistan

International Centre for Diarrhoeal Disease Research, Bangladesh

National Institute of Nutrition, Hanoi, Vietnam

ICP-OES

Children’s Hospital Oakland Research Institute, USA

ICP-MS

University of Colorado, Denver, USA

ETH Zurich, Switzerland

Oklahoma State University, USA

Which form? How much? How often?

Which form? How much? How often?

Multiple Micronutrient Powder (MNP) programs are being scaled up globally and present a golden opportunity for delivering preventive zinc to older infants and young children.