Nutritional deficiency is measured through several distinct lenses, including food access, dietary diversity, child growth, anaemia and nutrient biomarkers. The figures below span global estimates, historical WHO assessments, U.S. surveys and clinical trials, so the populations, dates and definitions matter.
Key Nutritional Deficiency Statistics
The most broadly useful figures include:
- In 2023, about 733 million people worldwide faced hunger, equivalent to roughly one in 11 people globally.
- In 2023, around 2.33 billion people worldwide experienced moderate or severe food insecurity.
- In 2022, more than 2.8 billion people worldwide could not afford a healthy diet.
- In pooled data from 2016–2022, only 34% of children aged 6–23 months worldwide met minimum dietary diversity.
- Global exclusive breastfeeding among infants under six months rose from 37.1% in 2012 to 48% in 2022.
- Global stunting among children under five fell from 26.3% in 2012 to 22.3% in 2022.
- Global wasting among children under five declined from 7.5% in 2012 to 6.8% in 2022.
- In 2024, 6.6% of children under five worldwide experienced wasting, equal to 42.8 million children.
- In 2023, 30.7% of women aged 15–49 worldwide had anaemia.
- In 2023, 35.5% of pregnant women aged 15–49 worldwide had anaemia.
- In the cited historical WHO estimate, 33% of preschool-age children worldwide had subclinical vitamin A deficiency.
- In the cited 2012 global estimate, 29.8% of school-age children had insufficient iodine intake.
- In NHANES 2007–2018, 3.6% of U.S. adults aged 19 and older met the serum vitamin B12 deficiency definition below 200 pg/mL.
- In NHANES 1999–2006, 18% of U.S. pregnant women had iron deficiency.
- In the cited Cochrane review, daily iron supplementation reduced anaemia at term by 70% in pregnancy trials.
- In the cited 2018 review, three randomized trials with 153 participants compared high-dose oral and intramuscular B12.
Contents
- Global food insecurity and healthy-diet access
- Child nutritional deficiency trends
- Micronutrient deficiency data
- U.S. iron and vitamin B12 statistics
- Outcomes and supplementation evidence
Global Nutritional Deficiency Statistics: Food Insecurity and Healthy-Diet Access
Food insecurity and diet affordability describe conditions that can increase deficiency risk, but neither is a laboratory diagnosis. The State of Food Security and Nutrition in the World 2024 reports that hunger, defined as undernourishment, affected about 733 million people worldwide in 2023, or roughly one in 11 people.
The same 2023 assessment estimated that about one in five people in Africa faced hunger. Around 2.33 billion people experienced moderate or severe food insecurity, including more than 864 million people in the severe category.
| Measure | Population or geography | Period | Result |
|---|---|---|---|
| Hunger | World | 2023 | About 733 million people; roughly one in 11 |
| Hunger | Africa | 2023 | About one in five people |
| Moderate or severe food insecurity | World | 2023 | Around 2.33 billion people |
| Severe food insecurity | World | 2023 | More than 864 million people |
Source: The State of Food Security and Nutrition in the World 2024. These are SOFI estimates and food-access measures, not diagnosed malnutrition or micronutrient biomarker results.
Healthy-diet affordability provides another broad indicator. More than 2.8 billion people worldwide could not afford a healthy diet in 2022; the modeled share was 71.5% in low-income countries compared with 6.3% in high-income countries.
In pooled data from 2016–2022, only 34% of children aged 6–23 months met minimum dietary diversity worldwide. About 65% of women aged 15–49 met that indicator in pooled data from 2020–2024, but dietary diversity is a proxy for adequacy rather than measured nutrient sufficiency.
Child Nutritional Deficiency Statistics: Stunting, Wasting and Low-Birthweight Trends
Child growth indicators capture forms of malnutrition that are related to nutrition but are not interchangeable with micronutrient deficiency. The global estimates in this section use WHO Child Growth Standards.
| Indicator | 2012 | 2022 | Population |
|---|---|---|---|
| Exclusive breastfeeding, under six months | 37.1% (25.7 million) | 48% (31.3 million) | Infants worldwide |
| Stunting | 26.3% (177.9 million) | 22.3% (148.1 million) | Children under five worldwide |
| Wasting | 7.5% (50.7 million) | 6.8% (45 million) | Children under five worldwide |
| Overweight | 5.5% (37 million) | 5.6% (37 million) | Children under five worldwide |
Source: The State of Food Security and Nutrition in the World 2024. Wasting prevalence does not accumulate repeated episodes through a year and can vary seasonally.
The 2030 exclusive-breastfeeding projection is 59%, below the 70% target, while stunting is projected at 19.5% if the post-baseline trend persists. These are forecasts rather than observed future values.
Regional variation is substantial. Oceania excluding Australia and New Zealand had the highest regional stunting prevalence at 44% in 2022, while Australia and New Zealand had the highest regional under-five overweight prevalence at 19.3%.
Under-five overweight is projected at 5.7% in 2030, almost twice the 3% global target. Overweight is a separate form of malnutrition, not nutritional deficiency itself.
UNICEF’s 2024 estimate put wasting at 6.6% of children under five worldwide, or 42.8 million children, including severe wasting at 1.9%, or 12.2 million children. The prevalence-based estimate likely undercounts cumulative annual cases because repeated episodes are not added together.
Micronutrient Deficiency Statistics: Anaemia, Vitamin A and Iodine
Anaemia is widespread but has nutritional and non-nutritional causes, including infection, so it should not be treated as synonymous with iron deficiency. The SOFI estimate placed anaemia among women aged 15–49 at 28.5% in 2012, or 520 million women, rising to 29.9% in 2019, or 571 million.
The same source projects 32.3% in 2030 against a 14.3% policy target. WHO’s Micronutrients Portal reports 30.7% of women aged 15–49, 35.5% of pregnant women and 30.5% of non-pregnant women in that age range had anaemia in 2023; it reports 39.8% of children aged 6–59 months in 2019.
Source: The State of Food Security and Nutrition in the World 2024 and WHO Micronutrients Portal. The estimates use different reporting periods and populations.
Vitamin A and iodine figures below are historical WHO estimates, not current surveillance. Subclinical vitamin A deficiency was estimated at 33% of preschool-age children, or 190 million children, and 15.3% of pregnant women, or 19.1 million women, in the cited 1995–2005 estimates.
| Historical WHO measure | Geography | Period or definition | Result |
|---|---|---|---|
| Preschool-child subclinical vitamin A deficiency | World | 1995–2005 estimates; serum retinol below 0.70 µmol/L | 33% (190 million) |
| Pregnant-woman subclinical vitamin A deficiency | World | 1995–2005 estimates; serum retinol below 0.70 µmol/L | 15.3% (19.1 million) |
| Preschool-child vitamin A deficiency | South-East Asia | 1995–2005 estimates | 49.9% |
| Preschool-child vitamin A deficiency | Africa | 1995–2005 estimates | 44.4% |
| Pregnancy vitamin A deficiency | Western Pacific | 1995–2005 estimates | 21.5% |
The same historical assessment reported clinical night blindness among 9.8% of pregnant women in the African Region and 9.9% in the South-East Asia Region. Clinical night blindness is a different measure from subclinical serum-retinol deficiency.
An estimated 29.8% of school-age children had insufficient iodine intake in the cited 2012 estimate, defined as urinary iodine below 100 µg/L. The corresponding estimate for the general population was 28.5%, representing about 1.88 billion people.
Source: Global nutrition policy review: What does it take to scale up nutrition action?. These are population-level iodine indicators, not individual diagnoses.
U.S. Nutritional Deficiency Statistics: Iron and Vitamin B12 Status
U.S. estimates show why definitions and biomarker cutoffs change the apparent prevalence. In NHANES 2007–2018, 3.6% of adults aged 19 and older met the serum vitamin B12 deficiency definition below 200 pg/mL, compared with 3.7% of adults aged 60 and older.
Using the broader insufficiency cutoff below 300 pg/mL, the estimates were 12.5% for adults aged 19 and older and 12.3% for those aged 60 and older. In NHANES 1999–2004, 3% of adults were below 200 pg/mL while 26% were below 350 pg/mL; those figures use different cutoffs.
Source: Vitamin B12: Health Professional Fact Sheet. These are survey estimates, not clinical diagnoses for every participant.
| U.S. measure | Population | Period | Result |
|---|---|---|---|
| Serum B12 deficiency, below 200 pg/mL | Adults 19+ | NHANES 2007–2018 | 3.6% |
| Serum B12 insufficiency, below 300 pg/mL | Adults 19+ | NHANES 2007–2018 | 12.5% |
| Iron deficiency | Pregnant women | NHANES 1999–2006 | 18% |
| Iron deficiency by trimester | Pregnant women, first, second, third trimester | NHANES 1999–2006 | 6.9%, 14.3%, 29.7% |
Depending on definition, reviewed studies found vitamin B12 deficiency in 3%–43% of community-dwelling older adults. Among older adults entering long-term care in the cited study, 14% were below 211 pg/mL and 38% below 407 pg/mL; atrophic gastritis affected about 2% of the general population and 8%–9% of adults aged 65 and older in the cited review.
For younger U.S. groups, 6% of White and Black toddlers aged 1–3 were iron deficient compared with 12% of Hispanic toddlers in the cited analysis. Approximately 18% of infants aged 6–12 months had inadequate iron intakes, while iron-deficiency anaemia among toddlers aged 12–35 months ranged from 0.9% to 4.4% by race/ethnicity and socioeconomic status.
Nutritional Deficiency Outcomes and Supplementation Statistics
Trial evidence describes studied populations and interventions, not guaranteed effects for every person. In the cited Cochrane review, daily iron supplementation of 9–90 mg during pregnancy reduced anaemia at term by 70% and iron deficiency at term by 57%.
Low birthweight occurred in 8.4% of births with daily iron supplementation versus 10.2% without supplementation in the pooled pregnancy evidence. The dose range, baseline risk and adherence varied across trials.
Other clinical populations show why deficiency risk is context-dependent. About 60% of patients with chronic heart failure had iron deficiency and 17% had iron-deficiency anaemia in the cited NIH review, while up to 60% of patients with colon cancer had iron deficiency at diagnosis; other cancers ranged from 29% to 46%.
Among 215 recent blood donors in a clinical trial, two-thirds without iron supplementation had not recovered lost iron by 24 weeks. This finding applies to frequent or recent donors, not the general population.
For vitamin B12 treatment, a 2018 Cochrane review included three randomized trials comparing high-dose oral and intramuscular therapy in 153 participants. The review found similar serum-B12 normalization, but rated the evidence low quality and did not establish equivalent results for every clinical outcome.
Vitamin B12 storage also affects how deficiency appears over time. The body stores about 1–5 mg, roughly 1,000–2,000 times a typical daily intake, an estimate that helps explain delayed symptoms but is not itself a prevalence statistic.
Source: Iron: Health Professional Fact Sheet and Vitamin B12: Health Professional Fact Sheet.