1 in 2 people reading this article are likely experiencing hidden hunger, in other words a lack of essential vitamins and minerals. That matters because these "micronutrients" are the micro drivers of functions such as our immune systems which keep us safe and healthy.
For the past 30 years scientists, program planners, policymakers, and funders have routinely used the large figure of 2 billion to estimate the number of people suffering from this hidden hunger. But a new study published in The Lancet Global Health, led by the Global Alliance for Improved Nutrition (GAIN) through the USAID Advancing Nutrition project suggests that this number is, in all likelihood, twice as big.
The study specifically found that over 1 in 2 children under the age of five and 2 in 3 women between the ages 15–49 worldwide are deficient in at least one micronutrient. Alarmingly, in many countries in Sub-Saharan Africa and South Asia 9 in 10 women are deficient, and this is largely due to poor diets that are high in starchy staple foods. But micronutrient deficiencies leave no country untouched. Even in high-income countries like the US and UK between 1 in 3 and 1 in 2 women are deficient. Iron deficiency alone afflicts over 20% of women in both countries. In the UK folate and vitamin D deficiencies among women are also high at around 20% each.
Because data were not universally available, the study only included women and young children, leaving two-thirds of the global population unaccounted for - school-age children, younger adolescents, older adolescent boys, men, and older adults. We don’t have enough data on these population groups to make a precise estimate worldwide, but the available evidence suggests they face relatively similar burden to that of women and young children.
For example, a study from India found that prevalence of deficiency in one or more micronutrients was similar between older (82%) and younger (83%) adolescents and boys (79%) and girls (86%). Another study from India found a similar burden among urban school-age children. For men, the data on micronutrient deficiencies is nearly entirely missing. But research (albeit limited) suggests that globally, prevalence of inadequate micronutrient intakes between men and women do not differ much. Finally, there is limited data on micronutrient deficiencies among older adults globally, but a population-based study in Germany found that over half were deficient in vitamin D and over a quarter were deficient in vitamin B12, while iron and zinc deficiencies were each around 10%.
Taken together, 1 in 2 of us are probably deficient in at least one micronutrient. And there are 29 essential micronutrients in total, most of which we have no data on - the problem could be even more widespread if we tracked all of these micronutrients.
Micronutrients are important because they promote the kinds of resilience needed in the face of repeated shocks caused by climate change, Covid-19 lockdowns, and conflicts. Pregnant and lactating women, infants and young children, adolescents, women of reproductive age, and older adults are at the developmentally vulnerable milestones of the human lifecycle, and stand to benefit from micronutrients, and suffer the effects of their deficiency.
What can be done about it? A greater focus is needed on making nutritious food (with high micronutrient content) more available, affordable, and desirable. A study by GAIN found that the most micronutrient dense foods include animal-source foods, dark green leafy vegetables, and pulses (beans, peas, and lentils). And a similar focus is still needed on fortification and supplementation to prevent or correct micronutrient deficiencies among vulnerable groups. GAIN is working with partners in all these domains, and this research underscores the importance of these food systems actions. Hidden hunger is less 'hidden' thanks to this study, and it must become less hidden in policy agendas.