At least four billion people worldwide have insufficient intake of riboflavin (vitamin B2), folate, vitamin C and iron, according to a study appearing August 29, 2024, in The Lancet Global Health.¹ Even worse, inadequacies of vitamin E, calcium and iodine were estimated to exist in at least five billion individuals.

“Most people—even more than previously thought, across all regions and countries of all incomes—are not consuming enough of multiple essential micronutrients,” stated coauthor Ty Beal, PhD, of the Global Alliance for Improved Nutrition (GAIN). “These gaps compromise health outcomes and limit human potential on a global scale.”

Other nutrients were also severely lacking among many of the world’s people, including vitamin A, thiamin (vitamin B1), niacin (vitamin B3), vitamin B6, vitamin B12, magnesium, selenium and zinc. Men had greater inadequacy of vitamins A, C and B6, thiamin, niacin, magnesium and zinc compared with women in the same country and age group, and women had greater inadequacy of vitamin B12, iodine, iron and selenium.

As examples of risks associated with nutrient inadequacies, the authors remarked that vitamin A deficiency is the leading preventable cause of blindness and plays a key role in immunity. Healthy immune function also requires adequate zinc. The protective role of folate against neural tube defects and stillbirths is well known. Iodine is also critical for pregnant women and those who are breastfeeding.

“The public health challenge facing us is immense, but practitioners and policymakers have the opportunity to identify the most effective dietary interventions and target them to the populations most in need,” senior author Christopher Golden of the Harvard Chan School of Medicine remarked.

The research team utilized data from the Global Dietary Database, the World Bank, and dietary recall survey responses to compare requirements for 15 micronutrients with nutrient intake in 185 countries or territories in 2018. Men and women were separately analyzed according to 17 different age groups. Estimated nutrient intakes did not include fortified foods or vitamin and mineral formulas and generally show a higher prevalence of inadequacy than blood biomarker data suggests.