For decades, nutrition and global health researchers and practitioners have stated that the number of people worldwide experiencing micronutrient deficiencies is 2 billion. However, the methods used to arrive at this estimate have not been readily available, which prevented researchers from updating this estimate.

Supported by USAID Advancing Nutrition, a group of researchers including consortium partner GAIN, and an advisory panel of experts managed by the Micronutrient Forum, set out to estimate the global and regional prevalence of deficiencies among preschool-age child and non-pregnant women of reproductive age. The team developed a transparent approach based on data availability, then shared detailed methods so other researchers can update the estimate as needed. Timely data on the burden of micronutrient deficiencies is essential to understanding what works where and whether we’re making progress.

Using existing biomarker data from 24 nationally representative surveys, researchers determined the global prevalence of deficiencies in one or more key micronutrients among women aged 15–49 and children under five—iron, zinc, folate in non-pregnant women and iron, zinc, and vitamin A in preschool-age children. Now published in the Lancet Global Health the paper estimates that globally, an estimated 56 percent (or 372 million) of preschool-age children are deficient in at least one of three key micronutrients. Sixty-nine percent (or 1.2 billion) of nonpregnant women are affected. Due to lack of data for men, older children and older adults, the total number could not be estimated, but is likely much greater than 2 billion.

Implementing partners like USAID Advancing Nutrition are working to increase the micronutrient intake of populations with improved diets, fortification of staple foods and condiments, crop biofortification, or supplementation. These efforts may reduce the burden of maternal and child morbidity, impaired cognitive development, and mortality.