Vitamin B12 deficiency identified as widespread health issue

Vitamin B12 deficiency, long recognized as a public‑health concern, impacts far beyond anemia. The shortage can damage the nervous system, cause irreversible neurological damage if untreated, and affect blood formation and DNA synthesis.

In the United States, about 2 %–4 % of adults are clinically deficient, while roughly 12 % have sub‑optimal levels. Prevalence rises with age and among groups such as bariatric‑surgery patients, vegans or vegetarians without supplementation, and individuals taking metformin or proton‑pump inhibitors.

Brazil lacks large population studies, but clinicians report the condition is relatively common, especially among older adults and people with gastrointestinal disorders that hinder absorption. The vitamin is absorbed after binding intrinsic factor in the stomach and is stored primarily in the liver, allowing a slow onset of symptoms that may begin with vague complaints before progressing to hematologic and neurological manifestations.