Newly published research indicates that 1 in 2 children under the age of five and 2 in 3 women aged 15-49 are affected by micronutrient deficiencies globally. This is equivalent to 372 million preschool children and 1.2 billion women. With these two population groups making up only one-third of the population worldwide, the total number of affected people is likely to be far larger once school-age children, adolescents, men and older adults are included in the estimate.
For over three decades it has been stated that micronutrients affect 2 billion people globally. However, this estimate has been based on the number of people with anemia, which is not equivalent to deficiencies in iron, zinc, folate, vitamin A, and other essential micronutrients. A global prevalence estimate based on individual-level biomarker data has been desperately needed.
With funding from USAID, the Global Micronutrient Deficiencies Research Group led by the Global Alliance for Improved Nutrition (GAIN) pooled and re-analyzed individual-level biomarker data on micronutrient status from nationally representative, population-based surveys to estimate the prevalence and number of preschool children (6–59 months) and non-pregnant women of reproductive age (15–49 years) with one or more micronutrient deficiencies, globally and regionally.
The analysis included 24 datasets from nationally representative surveys in 22 countries. Zinc was selected as one of three core micronutrients together with iron and vitamin A for preschool children, and iron and folate for women. Data on plasma/serum zinc concentrations in PSC and WRA were available in 16 and 15 datasets, respectively. Among preschool children, the prevalence of zinc deficiency was ≥20% (the cutoff used to indicate a public health problem) in 12 datasets, and 10–19% in 4 datasets. Among women, the prevalence of zinc deficiency was ≥20% in the 13 datasets from LMICs, 14% in United States and 10% in United Kingdom. The countries with the highest prevalence of zinc deficiency (>50%) among both population groups were Cambodia, Cameroon, Malawi and Vietnam, as well as Ecuador for women.
The dearth of micronutrient biomarker data has been well-recognized and several recommendations to address this problem have been published. Along with the authors of these new global estimates, IZiNCG hopes the results of this analysis highlight the need for more and improved data on micronutrient status, increased funding for programs to implement and scale-up interventions to prevent micronutrient deficiencies, and improved monitoring and evaluation of such programs.
Photo credit: World Bank photo collection