Vitamin B12, homocysteine and carotid plaque in the era of folic acid fortification of enriched cereal grain products
Bibliographic record
Abstract
BACKGROUND: Carotid plaque area is a strong predictor of cardiovascular events. High homocysteine levels, which are associated with plaque formation, can result from inadequate intake of folate and vitamin B12. Now that folic acid fortification is widespread in North America, vitamin B12 has become an important determinant of homocysteine levels. We sought to determine the prevalence of low serum levels of vitamin B12, and their relation to homocysteine levels and carotid plaque area among patients referred for treatment of vascular disease since folic acid fortification of enriched grain products. METHODS: We evaluated 421 consecutive new patients with complete data whom we saw in our vascular disease prevention clinics between January 1998 and January 2002. We measured total carotid plaque area by ultrasound and determined homocysteine and serum vitamin B12 levels in all patients. RESULTS: The patients, 215 men and 206 women, ranged in age from 37 to 90 years (mean 66 years). Most were taking medications for hypertension (67%) and dyslipidemia (62%). Seventy-three patients (17%) had vitamin B12 deficiency (vitamin B12 level < 258 pmol/L with homocysteine level > 14 mumol/L or methylmalonic acid level > 271 nmol/L). The mean area of carotid plaque was significantly larger among the group of patients whose vitamin B12 level was below the median of 253 pmol/L than among those whose vitamin B12 level was above the median: 1.36 (standard deviation [SD] 1.27) cm2 v. 1.09 (SD 1.0) cm2; p = 0.016. CONCLUSIONS: Vitamin B12 deficiency is surprisingly common among patients with vascular disease, and, in the setting of folic acid fortification, low serum vitamin B12 levels are a major determinant of elevated homocysteine levels and increased carotid plaque area.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
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".