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Record W2898612093 · doi:10.1093/gerona/gly185

Harm With High Levels of Serum B12 in Elderly Persons

2018· letter· en· W2898612093 on OpenAlexaff
J. David Spence

Bibliographic record

VenueThe Journals of Gerontology Series A · 2018
Typeletter
Languageen
FieldMedicine
TopicFolate and B Vitamins Research
Canadian institutionsWestern University
Fundersnot available
KeywordsHarmPsychologyMedicineGerontologyPsychiatrySocial psychology

Abstract

fetched live from OpenAlex

A recent report from the Newcastle 85+ study (1) presents the not unexpected finding that high plasma levels of total homocysteine (tHcy) were associated with increased cardiovascular events among elderly persons. However, it also reported the very surprising finding that high serum B12 levels were also associated with increased cardiovascular events. Figure 3 in the article shows a marked increase in cardiovascular risk with serum B12 levels above 600 pmol/L. However, it seems likely that such high serum B12 levels were due to vitamin supplements, most probably with cyanocobalamin. The Figure 1 shows the distribution of serum B12 among outpatients aged ≥85 years referred with transient ischemic attack or minor stroke to our urgent transient ischemic attack clinic. The reference range for serum B12 for our hospital is 145–569 pmol/L, so serum B12 levels >600 pmol/L are unphysiological, and therefore probably due mainly to B12 supplements. It has become apparent that the reason that B vitamin supplements intended to lower plasma tHcy were not efficacious for stroke prevention in the early randomized trials was that harm from cyanocobalamin among study participants with renal impairment obscured the benefit among partipants with good renal function (2). At age ≥80 years, the average estimated glomerular filtration rate is <60 (3).

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.011
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Commentary · Consensus signal: Commentary
Teacher disagreement score0.010
Threshold uncertainty score0.010

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.011
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0020.001
Scholarly communication0.0010.001
Open science0.0000.001
Research integrity0.0100.006
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.091
GPT teacher head0.351
Teacher spread0.260 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreCommentary

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations5
Published2018
Admission routes1
Has abstractno

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Same venueThe Journals of Gerontology Series ASame topicFolate and B Vitamins ResearchFrench-language works237,207