Global Micronutrient Deficiencies Affect Over Half of World Population
global micronutrient deficiencies half world population
A collaborative study conducted by Harvard T.H. Chan School of Public Health, UC Santa Barbara, and the Global Alliance for Improved Nutrition (GAIN) reveals a significant global issue: over half of the world’s population is not consuming adequate levels of vital micronutrients, such as calcium, iron, and vitamins C and E.
This pioneering research, published on August 29 in The Lancet Global Health, represents the first comprehensive global assessment of inadequate intake for 15 essential micronutrients crucial for maintaining health.
Micronutrient deficiencies are among the most pervasive forms of malnutrition worldwide, each deficiency bringing its own set of health risks—from complications during pregnancy to blindness and heightened vulnerability to infectious diseases.
While prior studies have estimated the availability and consumption of these micronutrients, this research takes a step further by assessing whether these intakes align with the recommended levels necessary for human health. It also delves into the specific inadequacies faced by both males and females throughout their lives.
Unprecedented Scope and Accessibility
“This study is a major advancement,” remarked Chris Free, co-lead author and research professor at UCSB. “Not only is it the first to estimate inadequate micronutrient intakes for 34 distinct age-sex groups across nearly every nation, but it also ensures that these methods and results are readily accessible to researchers and practitioners.”
Utilizing data from the Global Dietary Database, the World Bank, and dietary recall surveys across 31 countries, the researchers compared nutritional needs with actual intake in 185 countries.
They categorized populations into 17 age groups for both males and females, ranging from infancy to over 80 years old. The study assessed 15 critical vitamins and minerals, including calcium, iodine, iron, riboflavin, folate, zinc, magnesium, selenium, thiamin, niacin, and vitamins A, B6, B12, C, and E.
The findings revealed widespread inadequacies in the intake of nearly all evaluated micronutrients, with iodine, vitamin E, calcium, and iron being particularly deficient—affecting 68%, 67%, 66%, and 65% of the global population, respectively.
Over half of the population was found to be deficient in riboflavin, folate, and vitamins C and B6. Niacin intake was closest to sufficient, with 22% of the global population not meeting adequate levels, followed by thiamin (30%) and selenium (37%).
Gender Disparities and Regional Variations
The study uncovered significant gender disparities in micronutrient intake. Women were more likely to have inadequate intakes of iodine, vitamin B12, iron, and selenium compared to men within the same age groups and countries.
Conversely, men were more likely to be deficient in calcium, niacin, thiamin, zinc, magnesium, and vitamins A, C, and B6. While sex-based patterns of micronutrient inadequacy were evident, the study also highlighted that males and females aged 10-30 were particularly prone to insufficient calcium intake, notably in South and East Asia and sub-Saharan Africa. Low calcium intake was also observed in North America, Europe, and Central Asia.
“These findings are deeply concerning,” stated Ty Beal, senior technical specialist at GAIN. “The data suggests that a majority of the global population, across all regions and income levels, is not receiving adequate levels of multiple essential micronutrients. This deficiency undermines health outcomes and hampers human potential on a global scale.”
Senior author Christopher Golden, associate professor of nutrition and planetary health at Harvard Chan School, added, “The public health challenge before us is formidable, yet it also presents an opportunity for practitioners and policymakers to identify and implement the most effective dietary interventions, targeting the populations most in need.”
The researchers acknowledged that the lack of comprehensive data, particularly on individual dietary intake worldwide, may have limited the scope of their findings.
Reference
“Global estimation of dietary micronutrient inadequacies: a modelling analysis” by Simone Passarelli, Christopher M Free, Alon Shepon, Ty Beal, Carolina Batis, and Christopher D Golden, 29 August 2024, The Lancet Global Health. DOI: 10.1016/S2214-109X(24)00276-6
Simone Passarelli, a former doctoral student and postdoctoral research fellow in the Department of Nutrition at Harvard Chan School, co-led the study, with funding support from the National Institutes of Health (training grant 2T32DK007703-26).
