Vitamin B12status, cognitive decline and dementia: a systematic review of prospective cohort studies
Abstract
Poor vitamin B₁₂ status may lead to the development of cognitive decline and dementia but there is a large variation in the quality, design of and results reported from these investigations. We have undertaken a systematic review of the evidence for the association between vitamin B₁₂ status and cognitive decline in older adults. A database search of the literature to 2011 was undertaken, using keywords related to vitamin B₁₂ and cognition. All prospective cohort studies assessing the association of serum vitamin B₁₂ or biomarkers were included. Quality assessment and extraction of the data were undertaken by two researchers. The quality assessment tool assigns a positive, neutral or negative rating. Of 3772 published articles, thirty-five cohort studies (n 14 325 subjects) were identified and evaluated. No association between serum vitamin B₁₂ concentrations and cognitive decline or dementia was found. However, four studies that used newer biomarkers of vitamin B₁₂ status (methylmalonic acid and holotranscobalamin (holoTC)) showed associations between poor vitamin B₁₂ status and the increased risk of cognitive decline or dementia diagnosis. In general, the studies were of reasonable quality (twenty-one positive, ten neutral and four negative quality) but of short duration and inadequate subject numbers to determine whether an effect exists. Future studies should be of adequate duration (at least 6 years), recruit subjects from the seventh decade, choose markers of vitamin…
How strong is the evidence?
Evidence Hub reads this as a systematic review, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 14 participants or records.
Read the paper
Related studies
- Metabolic Syndrome: Updates on Pathophysiology and Management in 2021
- Environmental pollutants as risk factors for neurodegenerative disorders: Alzheimer and Parkinson diseases
- Antioxidants, inflammation and cardiovascular disease
- Application of Metabolomics in Alzheimer’s Disease
- Nutritional Importance of Carotenoids and Their Effect on Liver Health: A Review
- Nutritional essentiality of sulfur in health and disease
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.