Understanding Hidden Hunger: How many people have nutritional deficiencies globally?

October 20, 2025 •

4 min read

Recent research reveals that a staggering number of people suffer from 'hidden hunger', an ongoing crisis of vitamin and mineral deficiencies. While it was previously estimated that 2 billion people had deficiencies, new findings suggest the number is much larger once all population groups are considered, raising urgent questions about how many people have nutritional deficiencies across the world.

Quick Summary

Billions of people worldwide, including vulnerable groups like children and women, are affected by micronutrient deficiencies such as iron, vitamin A, and iodine. This silent epidemic, known as hidden hunger, significantly impacts global health, development, and economic potential, affecting both low- and high-income countries.

Key Points

Global Prevalence: Over 2 billion people are affected by micronutrient deficiencies globally, a number potentially far higher than previously thought.
Hidden Hunger Affects Many: Referred to as 'hidden hunger', these deficiencies particularly affect vulnerable groups like children and women of reproductive age.
Leading Deficiencies: The most common and impactful deficiencies are iron, iodine, and vitamin A, which can cause severe health issues like anemia, brain damage, and blindness.
Risk Factors: Insufficient dietary intake, malabsorption, increased nutritional needs, and climate change all contribute to deficiencies.
Variety of Symptoms: Symptoms range from fatigue and impaired immunity to cognitive and developmental issues.
Comprehensive Solutions: Strategies to address deficiencies include dietary diversification, food fortification, supplementation, and public education.
Action in All Income Levels: Deficiencies are not limited to low-income countries; significant rates exist in high-income nations, emphasizing that dietary quality is a universal issue.

The Staggering Scale of Global Micronutrient Deficiency

The World Health Organization (WHO) has highlighted that malnutrition, in all its forms, is one of the greatest global health challenges. This includes undernutrition (wasting, stunting, underweight), overweight, obesity, and inadequate vitamins or minerals, also known as 'hidden hunger'. The figures are immense, with a 2022 analysis in The Lancet Global Health estimating that 1 in 2 preschool-aged children and 2 in 3 women of reproductive age worldwide are affected by micronutrient deficiencies. The sheer scale of this problem indicates that far more than 2 billion people across the globe suffer from some form of hidden hunger, a number with serious implications for global health and development.

The Devastating Effects of Hidden Hunger

Micronutrient deficiencies compromise immune systems, hinder child growth and development, and limit human potential. The consequences often lead to severe and even life-threatening conditions, with nearly half of deaths among children under 5 linked to undernutrition. The impacts are serious and lasting, not only for individuals and families but for entire communities and nations. For instance, a lack of essential nutrients can cause visible and dangerous health conditions, but also lead to less obvious issues such as:

Reduced energy levels and chronic fatigue.
Impaired mental clarity and cognitive deficits.
Increased susceptibility to disease and infection.
Difficulties functioning in work, education, and community engagement.

Most Common Deficiencies and Their Impact

While hundreds of millions are affected by undernutrition, billions more suffer from specific micronutrient deficiencies. Among the most widespread and critical are:

Iron Deficiency: The most prevalent deficiency globally, leading to anemia. It affects 40% of pregnant women and 42% of children under 5 worldwide, causing fatigue, weakness, and impaired cognitive function.
Iodine Deficiency: Over 2 billion people are at risk. In severe cases, it can cause brain damage, miscarriages, and congenital anomalies. Milder deficiencies can still result in mental impairment that reduces intellectual capacity.
Vitamin A Deficiency: A leading cause of preventable blindness in children, it also increases the risk of severe infections.
Zinc Deficiency: Zinc is crucial for normal growth, immunity, and development. Deficiency can lead to increased infection susceptibility, impaired appetite, and skin lesions.

Who Is Most at Risk?

Nutritional deficiencies affect people of all ages and socioeconomic backgrounds, but certain groups are disproportionately vulnerable:

Children: Especially under the age of 5, children are highly susceptible to stunting and wasting due to undernutrition. Early life nutrition is crucial for long-term health and development.
Women: Women of reproductive age and pregnant women face a higher risk due to increased nutrient demands. Iron and folate deficiencies are particularly concerning during pregnancy.
Older Adults: As people age, they may experience reduced appetite, poorer nutrient absorption, or interact with medications that affect nutrient levels.
Low- and Middle-Income Countries: These regions bear a disproportionate burden due to limited access to affordable, nutrient-rich foods. Climate change further exacerbates this by impacting crop yields and nutritional value.
High-Income Countries: Surprisingly, deficiencies are common even in developed nations. For example, between 1 in 3 and 1 in 2 women in the US and UK are deficient in at least one micronutrient, highlighting that poor nutritional status isn't just about food scarcity but also about quality and dietary patterns.

Strategies for Combating Malnutrition

Addressing widespread nutritional deficiencies requires multi-pronged, coordinated efforts. Key strategies include:

Dietary Diversification: Promoting the consumption of a wide variety of nutrient-rich foods, including fruits, vegetables, legumes, and animal products, is foundational.
Food Fortification: Adding essential vitamins and minerals to commonly consumed staple foods, such as iodizing salt or fortifying wheat flour with iron and folic acid, is a proven public health strategy.
Biofortification: Using traditional plant breeding or genetic engineering to increase the nutrient density of crops.
Supplementation: Providing targeted supplements to vulnerable populations, such as pregnant women and young children, to address specific deficiencies.
Nutrition Education: Increasing public awareness about healthy eating habits and the importance of a balanced diet.

A Comparison of Global Intervention Strategies


Strategy	Target Audience	Speed of Impact	Cost-Effectiveness	Key Considerations
Dietary Diversification	All populations	Slow, requires long-term change	Moderate to High	Requires education, access to varied food sources, and sustained behavior change.
Fortification	Population-wide	Immediate, broad impact	High (for public health)	Requires government regulation, food industry cooperation, and robust monitoring.
Supplementation	Specific high-risk groups	Rapid and targeted	Moderate (variable)	Ensures specific nutrients are delivered but requires sustained programs and adherence.
Biofortification	All populations	Long-term	Moderate	Sustainable, but takes time to develop and distribute new crop varieties.

Conclusion: A Call for Coordinated Action

The question of how many people have nutritional deficiencies reveals a profound and pervasive global health challenge. With billions affected by some form of 'hidden hunger', the crisis extends beyond mere food scarcity and includes the quality and balance of nutrients consumed. While significant progress has been made, particularly in reducing some deficiencies like Vitamin A and protein-energy malnutrition, critical disparities persist across different regions, genders, and age groups. Combating this silent epidemic demands a sustained, multi-sectoral approach that integrates nutrition education, food fortification, targeted supplementation, and resilient food systems into policy and practice. Only through coordinated global and national efforts can the long-term burden of nutritional deficiencies be mitigated, ensuring a healthier and more productive future for all.

For more information on malnutrition, you can visit the World Health Organization's fact sheets on the topic.

Frequently Asked Questions

'Hidden hunger' refers to deficiencies in vitamins and minerals, or micronutrients, that are essential for the body's growth and proper functioning. It can lead to health problems even if a person consumes enough calories.

Women of reproductive age, pregnant women, and children under the age of five are at the highest risk, particularly in low- and middle-income countries. However, older adults and those with certain diseases are also vulnerable globally.

Globally, the most common deficiencies are iron, iodine, and vitamin A. Zinc and folate deficiencies are also significant public health concerns.

Yes, it is possible to be a healthy weight or even overweight and still have a nutritional deficiency. This can happen if your diet lacks variety and key vitamins and minerals.

Symptoms can vary depending on the specific deficiency but often include fatigue, weakened immune system, hair and skin changes, mood shifts, and poor wound healing.

Nutritional deficiencies are primarily diagnosed through blood tests and urinalysis, which can measure the levels of various vitamins and minerals in the body.

Effective prevention strategies include promoting a diverse diet, fortifying commonly consumed foods with essential nutrients, and providing supplements to at-risk individuals.