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50/100

✓ Peer-reviewed alzhub usefulness score 50 out of 100. Lewy body dementia

Topic: Brain proteins, microglia and lab models

Plain-language summary

There are many reasons for reviewing the neurology of vitamin-B12 and folic-acid deficiencies together, including the intimate relation between the metabolism of the two vitamins, their morphologically indistinguishable megaloblastic anaemias, and their overlapping neuropsychiatric syndromes and neuropathology, including their related inborn errors of metabolism. Folates and vitamin B12 have fundamental roles in CNS function at all ages, especially the methionine-synthase mediated conversion of homocysteine to methionine, which is essential for nucleotide synthesis and genomic and non-genomic methylation. Folic acid and vitamin B12 may have roles in the prevention of disorders of CNS development, mood disorders, and dementias, including Alzheimer's disease and vascular dementia in elderly people.

What this study adds

Evidence grade: Low

This is a narrative review. This review discusses how folate and vitamin B12 are involved in basic nervous system processes and notes they may have roles in preventing dementias including Alzheimer's disease. It does not report any trial result showing that taking these vitamins prevents or treats Alzheimer's disease.

Taken from this record’s own fields, not from reading the paper. The grade is assigned from the abstract’s wording; what that means.

Cite this study APA, Vancouver, BibTeX · download .bib or .ris

APA 7th

Reynolds, E. (2006). Vitamin B12, folic acid, and the nervous system. The Lancet. Neurology. https://doi.org/10.1016/s1474-4422(06)70598-1

Vancouver

Reynolds E. Vitamin B12, folic acid, and the nervous system. The Lancet. Neurology. 2006. doi:10.1016/s1474-4422(06)70598-1. PMID: 17052662.

BibTeX

@article{reynolds2006-17052662,
  author  = {Reynolds, E.},
  title   = {{Vitamin B12, folic acid, and the nervous system}},
  journal = {The Lancet. Neurology},
  year    = {2006},
  doi     = {10.1016/s1474-4422(06)70598-1},
  pmid    = {17052662},
  url     = {https://doi.org/10.1016/s1474-4422(06)70598-1}
}

Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.

How to read this study

Design: this is a narrative review. It summarises a field without a fixed search method, so it shows how authors read the evidence rather than measuring it. Use it to find the primary studies, not as a result in itself.
Size: the record gives no participant count. Look for one in the original before trusting a pattern.
Effect: the record gives no effect size, so the summary above cannot say how large any difference was.

What the evidence grade means here

This page is graded low. alzhub.org assigns the grade automatically from keywords in the abstract, not from reading the paper. Low means the abstract matched neither pattern. It is the default label, and it does not mean the work is poor; many sound lab and imaging papers land here. It can add at most 5 of the 100 points in the study score, and it is a label about design, not a verdict on whether the findings are true.

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Key findings

There are many reasons for reviewing the neurology of vitamin-B12 and folic-acid deficiencies together, including the intimate relation between the metabolism of the two vitamins, their morphologically indistinguishable megaloblastic anaemias, and their overlapping neuropsychiatric syndromes and neuropathology, including their related inborn errors of metabolism.
Folates and vitamin B12 have fundamental roles in CNS function at all ages, especially the methionine-synthase mediated conversion of homocysteine to methionine, which is essential for nucleotide synthesis and genomic and non-genomic methylation.
Folic acid and vitamin B12 may have roles in the prevention of disorders of CNS development, mood disorders, and dementias, including Alzheimer's disease and vascular dementia in elderly people.

Why it matters

This review discusses how folate and vitamin B12 are involved in basic nervous system processes and notes they may have roles in preventing dementias including Alzheimer's disease. It does not report any trial result showing that taking these vitamins prevents or treats Alzheimer's disease.

Study details

Evidence strengthLow

How this study scored 50/100

Published in a leading specialty journal. Scored zero for study design, sample size, effect reported, studied in people and randomized / blinded because the record does not state it.

Component	Points	Why
Journal tier	9 / 10	Tier 2 — leading specialty journal (The Lancet. Neurology)
Journal's citation record	3 / 4	The Lancet Neurology: journal h-index 457 (OpenAlex, 2026-10-29)
Study design	0 / 12	No study design recorded — scores zero, not guessed (not stated in the record — scored 0)
Strength of evidence	1 / 5	Rated “low” in our summary
Peer-review validation	10 / 10	Peer-reviewed. Published as an article in a named peer-reviewed journal.
How recent	1 / 5	2006 — older than 20 years, still counted
Sample size	0 / 4	Participant count not stated — scores zero (not stated in the record — scored 0)
Effect reported	0 / 3	No effect size reported — scores zero (not stated in the record — scored 0)
Studied in people	0 / 3	Not stated whether this was studied in people — scores zero (not stated in the record — scored 0)
Randomized / blinded	0 / 2	No randomization or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	6 / 7	Cited 866 times (OpenAlex, 2026-10-10)
Citations per year	4 / 5	39.4 citations a year over 22 year(s) since 2006
Impact for its field and year	4 / 6	Cited 15.5× the average for papers of its field and year (OpenAlex FWCI)
Cited by studies here	2 / 6	Cited by 9 other studies in this library
Still being cited	3 / 4	Cited 157 times in 2024–2026 (2026 still in progress; OpenAlex)
Senior author's track record	3 / 4	Last-listed author Edward H. Reynolds: h-index 56 (OpenAlex, whole career)
Institution's track record	1 / 3	King's College London: institution h-index 1,348 (OpenAlex)
Multicenter collaboration	1 / 3	OpenAlex lists 2 institution(s) in 1 country
Indexed in PubMed	2 / 2	Indexed in PubMed (PMID 17052662)
Free to read	0 / 2	Behind a paywall — scores zero
Total	50 / 100	—

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