Module 3. Biomarker selection and specimen handling

Vitamin A


Iron deficiency

Iron deficiency anemia


Vitamin B12


Vitamin D


Overview of specimen collection containers, storage and transport conditions


Many factors drive the selection of indicators. Some of these factors relate to participants, for example the acceptability and feasibility of the collection methods. Others concern field work (the ease of specimen collection, processing, storage, and transportation) and laboratory issues such as equipment, training, reagents, and costs. All these factors must be considered during the planning stage of the survey.

This module provides information to guide the selection of appropriate and reliable biomarkers, types of specimens, and methods of collection and analysis applicable to large micronutrient surveys. For each micronutrient there is a discussion of: specimen collection and management, biomarker analysis, an approximate budget, and how to interpret results. Issues of quality control are described where appropriate. The recommended collection containers, processing, storage and transport conditions for different specimen types are summarized in Table 3.11 at the end of the module. Costs have been calculated based on prices known in 2019. Actual costs for analyses may differ greatly from one laboratory to another.

Advice about the most suitable indicators and methods change periodically. During the planning phase, it is advisable to review the latest recommendations and consult with appropriate experts. Review papers on micronutrient status assessment developed under the Biomarkers of Nutrition for Development (BOND) program are shown in Box 3.1.

Best practices for haemoglobin measurement in population-level anaemia surveys - Technical brief

This brief describes the current best practices for haemoglobin measurement. It provides guidance for people who are planning or implementing field surveys that will assess anaemia prevalence at a population level. Published by WHO, 2024.


Instructions for estimating anaemia prevalence_2024

This document provides instruction for how to prepare and clean raw hemoglobin data as well as how to estimate anemia prevalence in a population.


Adjusting hemoglobin for elevation

Journal article: Reexamination of hemoglobin adjustments to define anemia: altitude and smoking. Sharma AJ et al. Ann. N.Y. Acad. Sci. ISSN 0077-8923


Serum ferritin concentrations for the assessment of iron status in individuals and populations: technical brief

This technical brief aims to provide summarized information about the use of serum ferritin for assessing iron status in individuals and populations. It is a compilation of the current World Health Organization ( WHO) recommendations on the topic and summarizes the cut-off values for describing iron stores and the chronology of their establishment. It also includes considerations for assessment of the risk of iron overload.