ArticleThe American journal of clinical nutrition2021
Fewer US adults had low or transitional vitamin B12 status based on the novel combined indicator of vitamin B12 status compared with individual, conventional markers, NHANES 1999-2004.
Article in The American journal of clinical nutrition, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
7 citing papers in PubMed, 8 citations in OpenAlex.
- KDIGO 2026 Clinical Practice Guideline for Anemia in Chronic Kidney Disease (CKD): a commentary from the European Renal Best Practice (ERBP).Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association · 2026Article
- The Diagnostic Accuracy of Methylmalonic Acid to Detect Inadequate Vitamin B-12 Status Relative to 3cB-12 Was Higher Compared with That of Total Cobalamin and Total Homocysteine in a Cross-Sectional Survey of Apparently Healthy US Adults.Current developments in nutrition · 2026Article
- Vitamin BNutrients · 2026Review
- Effect of Mitochondria-Derived Methylmalonic Acid on Progress and Mortality Risk in US Adults With Cardiovascular-Kidney-Metabolic Syndrome.Journal of the American Heart Association · 2026Article
- Vitamin BInternational journal of molecular sciences · 2024Review
- Vitamin B12 deficiency and neuropsychiatric symptoms in Lebanon: A cross-sectional study of vegans, vegetarians, and omnivores.PloS one · 2024Article
- Multi-omic profiling of plasma reveals molecular alterations in children with COVID-19.Theranostics · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 3 institutions in 1 country.
Funding
Abstract
backgroundElevated plasma methylmalonic acid (MMA) and/or total homocysteine (tHcy), as well as low serum vitamin B12 and/or holotranscobalamin (holoTC) are indicative of vitamin B12 deficiency. Combined indicators (cB12), which pool some or all 4 markers into an index, may be a more reliable diagnostic tool to overcome inconclusive diagnoses with individual markers.
objectivesWe aimed to describe different cB12 score combinations and estimate the prevalence of low or transitional vitamin B12 status compared with individual markers.
designUsing cross-sectional data for B12, MMA, and tHcy in persons ≥20 y participating in NHANES 1999-2004 (n = 12,335), we examined raw and covariate-adjusted regression models to assess determinants of 3cB12 (all 3 markers) and combinations of 2cB12 (2 markers).
results3cB12 was significantly associated with B12 (Spearman r = 0.75), MMA (r = -0.70), and tHcy (r = -0.59). The 3cB12 reference interval (2.5th to 97.5th percentile) was -0.538 to 1.60. In covariate-adjusted models, we found no association of 3cB12 with age; adult females and users of B12 supplements had higher, while adults with advanced chronic kidney disease had lower 3cB12 levels regardless of race-Hispanic origin group (self-reported). Only 2.7% of adults had low or transitional vitamin B12 status using the proposed cB12 cutoff of ≤-0.5, while the prevalence of low (or low-normal) status depended on the selected individual marker and its cutoff: 2.2% and 13% for B12 < 148 and 148-222 pmol/L, respectively; 6.0% for MMA exceeding an age-specific cutoff (250-320 nmol/L); and 8.4% for tHcy > 13 µmol/L. The reference intervals for B12, MMA, and tHcy overlapped from the low (<-2.5) to the transitional (-2.5 to -0.5) and to the adequate (>-0.5) cB12 categories.
conclusionsVitamin B12 deficiency may be overestimated among US adults when individual, conventional markers are used. When only 2 markers are available, the combination of B12 and MMA provides results comparable to 3cB12.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.