07/01/2026
Vitamin B12 deficiency is often framed as a niche nutritional issue, yet population-scale data suggest its clinical burden may be far larger, and rising.
A 2026 analysis (doi: 10.3389/fnut.2025.1701661) of Brazil’s national health system examined 84 million vitamin B12 laboratory tests collected between 2016 and 2023, linking results with hospitalization records. Over this period, B12-related hospitalizations increased by 32%, spanning neurological, cardiovascular, psychiatric, hematologic, and gastrointestinal conditions, indicating a growing, multisystem healthcare burden despite widespread testing.
Why this matters beyond Brazil: In the U.S. and other high-income countries, average vitamin B12 intake often sits near minimum requirements, particularly among older adults, individuals with impaired absorption, and those using common medications (e.g., metformin, proton pump inhibitors). Supporting evidence from neuroimaging and biomarker studies (PMID: 39927551) shows that functional neurological changes can emerge even when serum B12 levels fall within currently defined “normal” ranges, suggesting that delayed or threshold-based diagnosis may miss clinically meaningful insufficiency.
The Brazilian data likely reflect a broader pattern (not a country-specific anomaly) where vitamin B12 deficiency is detected after downstream complications develop, rather than during earlier, preventable stages.
Limitations: The hospitalization data are specific to Brazil and observational in nature. Hospital records capture severe outcomes and may underestimate subclinical disease. However, the scale and consistency of the signal suggest a probable gap between laboratory sufficiency and functional health protection.
Together, these findings support rethinking vitamin B12 adequacy as a public health issue of early detection and prevention, rather than one defined solely by anemia or late-stage clinical presentation.
