Most nutrient deficiencies are surprisingly poorly tracked at a global level — there's no worldwide database monitoring vitamin C or magnesium status country by country over time. Anemia is the clear exception. Because it's a core World Health Organization monitoring indicator, data aggregated by Our World in Data (sourced from WHO) covers 205 countries and territories from 2000 to 2023 — 23 continuous years, the most complete nutrition-adjacent dataset available anywhere.
Why anemia specifically gets this level of tracking
Anemia — most commonly caused by iron deficiency, though also linked to vitamin B12 and folate deficiency — is tracked so extensively because it's measurable via a relatively simple, low-cost blood test (hemoglobin concentration) that's practical to administer in large population health surveys, even in resource-limited settings. This is in contrast to something like vitamin D or zinc, where population-level testing is more expensive and logistically harder to scale globally.
What the data shows: pregnant women and women of reproductive age carry the highest burden
Across the tracked period, anemia prevalence has consistently been highest among pregnant women and women of reproductive age (15–49), compared to the general population or to men specifically. This pattern reflects the additional iron demands of menstruation and pregnancy — iron losses that a typical diet doesn't always fully offset, especially in regions where iron-rich food access or prenatal care is limited.
The trend over time: real, if uneven, progress
Because this dataset spans 23 years rather than a single snapshot, it allows something most nutrition data can't: an actual trend line. Global anemia prevalence has shown gradual improvement over the tracked period in many regions, correlating with expanded prenatal iron supplementation programs, improved food fortification, and general healthcare access gains — though progress has been uneven across regions, and anemia remains a substantial global health burden even where rates have declined.
What this global picture means closer to home
Even in countries with strong healthcare infrastructure, iron deficiency and anemia remain common in specific risk groups — menstruating women, pregnant women, vegetarians and vegans, and endurance athletes chief among them. The global data underscores that this isn't a problem confined to any one region; it's a consistently high-prevalence condition wherever iron demand is elevated relative to intake.
If you fall into one of these higher-risk groups, our iron deficiency test walks through the specific symptoms and risk factors worth checking before assuming fatigue is "just stress."
Why anemia data is the exception, not the rule
It's worth understanding why this level of global tracking exists for anemia specifically and almost nowhere else in nutrition. Anemia is a WHO "core indicator" — one of a small set of health metrics the organization specifically prioritizes for standardized, comparable, ongoing measurement across member countries, largely because it's both a serious public health burden and practically feasible to measure via hemoglobin testing even in lower-resource healthcare settings. Most other nutrient deficiencies lack an equivalently simple, scalable, cheap test, which is the primary reason global tracking data for something like zinc or vitamin C essentially doesn't exist, despite both being genuinely common deficiencies.
What the regional variation actually looks like
While this article focuses on the overall global pattern, the underlying 205-country dataset also reveals substantial regional variation — anemia prevalence differs meaningfully between regions with different food security profiles, healthcare access, and prevalence of conditions like malaria (which can contribute to anemia independent of iron intake). This means a "global average" figure, while useful for understanding overall scale, can obscure meaningful differences in both prevalence and underlying cause between different parts of the world.
Source: Our World in Data, aggregating World Health Organization anemia prevalence indicators, covering 205 countries/territories, 2000–2023.