Majority of global population found deficient in 15 essential micronutrients

30 Aug 2024 --- According to a new study by researchers at Harvard TH Chan School of Public Health, UC Santa Barbara (UCSB), and the Global Alliance for Improved Nutrition (GAIN), more than half of the global population consumes inadequate levels of several micronutrients essential to health including calcium, iron and vitamins C and E. The researchers claim it is the first study to provide global estimates of inadequate consumption of 15 critical micronutrients.

The study, published in The Lancet Global Health, observes that micronutrient inadequacies may be more severe than previously thought and differ between men and women. The findings provide a roadmap for action by showing which population groups are at risk of deficiency for specific nutrients.

“Our study is a big step forward,” says Chris Free, research professor at UCSB and co-lead author. “Not only because it is the first to estimate inadequate micronutrient intakes for 34 age-sex groups in nearly every country, but also because it makes these methods and results easily accessible to researchers and practitioners.”

Dietary database and recall surveys

The researchers used data from the Global Dietary Database and the World Bank, as well as dietary recall surveys in 31 countries, to compare nutritional requirements with nutritional intake among the populations of 185 countries.

They divided populations into men and women belonging to 17 age groups — zero to 80 in five-year spans, and an 80+ group. The assessment assessed levels of calcium, iodine, iron, riboflavin, folate, zinc, magnesium, selenium, thiamin, niacin and vitamins A, B6, B12, C and E.

The study found significant inadequacies for nearly all of the evaluated micronutrients, especially for iodine (68%), vitamin E (67%), calcium (66%) and iron (65%), for the global population. The results excluded fortification as a potential source of additional nutrients.

“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,” says Christopher Golden, associate professor of nutrition and planetary health at Harvard Chan School, US, and senior author of the study.

Over half of the study population consumed inadequate levels of riboflavin, folate and vitamins C and B6. Niacin intake was closest to sufficient, with 22% of the global population consuming inadequate levels, followed by thiamin (30%) and selenium (37%).

Patterns by gender

Inadequate intake of iodine, vitamin B12, iron and selenium was higher for women than men within the same country and age groups. Compared to women, more men consumed inadequate levels of calcium, niacin, thiamin, zinc, magnesium and vitamins A, C and B6.

The researchers also observed that males and females ages 10–30 were most prone to low levels of calcium intake, especially in South and East Asia and sub-Saharan Africa. Calcium intake was also low across North America, Europe and Central Asia.

“These results are alarming,” says Ty Beal, senior technical specialist at GAIN. “Most people — even more than previously thought, across all regions and countries of all incomes — are not consuming enough of multiple essential micronutrients. These gaps compromise health outcomes and limit human potential on a global scale.”

Micronutrient deficiencies are one of the most common forms of malnutrition globally. The researchers noted that a lack of available data, especially on individual dietary intake worldwide, may have limited their findings.

Meanwhile, Zero Hidden Hunger EU, a multi-partner European consortium led by University College Cork, Ireland, received close to €10 million (US$10.7 million) in funding to research micronutrient deficiencies over the next four years. Zero Hidden Hunger EU aims to estimate prevalence and health costs and develop tailored solutions.

By Inga de Jong

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