Event Summary: Half of young children and two- thirds of women of reproductive age suffer from 'hidden hunger'

Micronutrient deficiency could be much more widespread than previously believed, with half of children of preschool age and two-thirds of women of reproductive age around the world facing so-called hidden hunger, researchers say.

The study recently published in Lancet Global Health examined data sets from 22 countries between 2003 and 2019 looking for deficiencies in three key micronutrients: iron, zinc, and vitamin A. According to the study, conducted by the Global Alliance for Improved Nutrition (GAIN), at least one of the three micronutrients was deficient in 372 million preschool-aged children — 56 per cent — and 1.2 billion non-pregnant women of reproductive age — 69 per cent. They also found that women and children in South Asia, Sub-Saharan Africa and the Pacific were particularly vulnerable, but cautioned that "estimates are uncertain due to the scarcity of population-based micronutrient deficiency data."

During an online event on October 17th to discuss the study, Dr. Mduduzi Mbuya, GAIN's Director of Knowledge Leadership, noted that “hunger has increased by about 46 million since 2020" and that "deficiencies of micronutrients can result in a compromised immune system, hinder normal human growth and development, and affect human economic potential worldwide.”

Women and young children make up one third of the total global population, and researchers also believe the prevalence of deficiencies is much larger than the current data suggest. If school-age children, adolescents, men, and older adults were included, the problem would be much more widespread, they suggested.

According to Jonathan Gorstein, a Senior Program Officer at the Bill & Melinda Gates Foundation, these data gaps present a major challenge. “We need really robust and accurate data on vitamin and mineral deficiencies,” he said. World events, he added, hinder research efforts. “It’s noteworthy,” said Gorstein, “that the situation in many countries may have actually become worse since the publication of this paper due to the global pandemic and increases in food prices and supply distributions resulting from the Ukraine War.”

Micronutrient deficiencies are highest in lower income countries where nutrient-rich foods including meat and dark green vegetables are in shorter supply and the diet is based on rice, wheat, and maize, according to Dr. Saskia Osendarp, Executive Director of the Micronutrient Forum. These foods provide calories, but fewer vitamins and minerals.

“We now have reliable estimates in women of reproductive age and children,” Dr. Osendarp said, “suggesting that 1.6 billion women and children are micronutrient deficient. The implications are dire.”

Nita Dalmiya, a senior nutrition adviser at UNICEF, provided some additional background: “Among children six to 23 months, about half … are not fed the minimum recommended number of meals. Less than one-third of children are fed the minimally diverse diets they need to grow and develop.”

Severe deficiencies don’t just affect cognitive development and related challenges. They also make people more vulnerable to diseases such as diabetes. Specific nutrients, which were examined as part of the study, play important roles in overall health. For example, iron, iodine, and folic acid are important for brain development; zinc and vitamin D contribute to physical growth; and vitamin A is important for bone, skin, and eye health.

“Micronutrient deficiencies really have profound impacts in all stages of the life cycle,” said Dr. Osendarp, adding that they contribute to “adverse pregnancy outcomes and they increase the risk of chronic diseases in children later in life.”

Citing research by Nutrition International, Dr. Osendarp said that scaling up antenatal micronutrients could result in fewer deaths caused by nutrition-related non-communicable diseases. “It could help prevent six million cases of hypertension and three million cases of diabetes,” she said. “Even though the immediate impacts are less visible, [they] can impact the lives of an entire generation.

Among many potential solutions is biofortification – developing crops that are more nutritious and drought-resilient. Unlike conventional fortification, which occurs during processing, biofortification uses selective breeding or genetic engineering to grow plants that are more nutritious. “Our food systems need to embrace diversity of production,” Dr. Osendarp said, “and they need to deliver large-scale food fortification and invest in micronutrient-rich, climate resilient food crops.”

The panel agreed that micronutrient deficiency is a much larger problem than previously reported, but Dr. Osendarp contended that concerted efforts on a global scale could turn the tide. “We have readily available, scalable, and impactful low-cost solutions that we can use to tackle this problem,” she said. “We have not invested enough into these integrated holistic approaches across food, health, and social protection systems … As with any public health challenge, data is critical for us to drive agendas forward and to make progress in reducing hidden hunger.”

The study was supported by USAID's Advancing Nutrition project and involved a team of global micronutrient experts, including an advisory panel brought together by the Micronutrient Forum.