🇺🇸 영어 원문
Vitamin B12 is best known for helping the body make DNA, red blood cells, and healthy nerve tissue. But research suggests that simply meeting the current minimum standard may not always be enough, especially for older adults.
A UCSF led study found that healthy older people with lower vitamin B12 levels, even when those levels still fell within the accepted normal range, showed signs of subtle neurological and cognitive problems. The findings raise a provocative possibility: some people may be told their B12 status is fine while their brains are already showing early signs of strain.
The study, published in Annals of Neurology, looked at older adults who did not have dementia or mild cognitive impairment. Even in this relatively healthy group, lower levels of active B12 were linked to slower thinking, slower visual processing, and more visible injury in the brain’s white matter. White matter is made up of the nerve fibers that allow different parts of the brain to communicate.
The work was led by senior author Ari J. Green, MD, of the UCSF Departments of Neurology and Ophthalmology and the Weill Institute for Neurosciences. Green and his colleagues said the results call attention to a possible weakness in current B12 guidelines. The minimum threshold used to define deficiency may not capture early functional changes in the nervous system.
"Previous studies that defined healthy amounts of B12 may have missed subtle functional manifestations of high or low levels that can affect people without causing overt symptoms," said Green, noting that clear deficiencies of the vitamin are commonly associated with a type of anemia. "Revisiting the definition of B12 deficiency to incorporate functional biomarkers could lead to earlier intervention and prevention of cognitive decline."
Researchers enrolled 231 healthy participants through the Brain Aging Network for Cognitive Health (BrANCH) study at UCSF. The participants had an average age of 71, and none had dementia or mild cognitive impairment.
Their average blood B12 level was 414.8 pmol/L, far above the U.S. minimum cutoff of 148 pmol/L. Instead of relying only on total B12, the researchers focused on the biologically active form of the vitamin, which may better reflect how much B12 the body can actually use.
After adjusting for age, sex, education, and cardiovascular risk factors, the team found that participants with lower active B12 had slower processing speed on cognitive tests. The effect was stronger with older age. They also had delayed responses to visual stimuli, pointing to slower visual processing and reduced brain signaling efficiency.
MRI scans added another warning sign. Participants with lower active B12 had a higher volume of white matter lesions, which are areas of brain injury that have been linked to cognitive decline, dementia, and stroke risk.
The study focused on older adults, a group that may be especially sensitive to lower B12 because absorption can become less efficient with age. Some medications, digestive conditions, and diets low in animal based foods can also increase the risk of low B12.
Co-first author Alexandra Beaudry-Richard, MSc, said the findings suggest that low but technically normal B12 could have broader effects than previously recognized. These levels could "impact cognition to a greater extent than what we previously thought, and may affect a much larger proportion of the population than we realize."
🇰🇷 한국어 요약
비타민 B12 는 우리 몸이 DNA 와 적혈구를 만들고 신경 조직을 건강하게 유지하는 데 중요한 역할을 합니다. 하지만 최근 연구에 따르면, 현재 정해진 최소 기준치만 충족한다고 해서 항상 충분한 것은 아니라고 합니다. 특히 나이가 많은 사람들에게서 그렇습니다.
UCSF 에서 주도한 연구 결과, 정상 범위 내에 있더라도 비타민 B12 수치가 낮은 건강한 노년층에서 미세한 신경 및 인지 문제의 징후가 발견되었습니다. 이는 뇌가 이미 스트레스를 받고 있는데도 수치가 정상이라고 오해할 수 있음을 의미합니다. 연구팀은 뇌의 백색질 손상과 인지 처리 속도 저하가 활성 B12 수치와 연관이 있음을 확인했습니다. 따라서 기존의 결핍 기준을 재검토하여 뇌 건강을 더 일찍 보호할 필요가 있다는 결론을 내렸습니다.
🔑 핵심 단어 (Vocabulary)
- Neurological – 신경계의 – signs of subtle neurological problems
- Cognitive – 인지적인 – slower thinking and cognitive problems
- Deficiency – 결핍 – define deficiency may not capture
- Biomarkers – 생체 표지자 – incorporate functional biomarkers
- Intervention – 개입, 중재 – lead to earlier intervention
- Stimuli – 자극 – responses to visual stimuli
- Lesions – 병변, 손상 – higher volume of white matter lesions
- Absorption – 흡수 – absorption can become less efficient
- Dementia – 치매 – linked to cognitive decline, dementia
- Threshold – 문턱, 기준치 – minimum threshold used to define
🔗 원문 링크
https://www.sciencedaily.com/releases/2026/05/260522031001.htm