Authors
Ashley M Foulkrod, Elliott V Rebello, Thomas A Beltran, Erica L Gigas, Carlos J Maldonado
Published in
Laboratory medicine. Volume 57. Issue 6. Oct 05, 2026.
Abstract
Total serum vitamin B12 levels may not align with biomarkers of circulating active vitamin B12 or intracellular vitamin B12-dependent metabolism. We estimated the population prevalence of marker-defined discordance among US adults and examined the influence of kidney function.
We analyzed National Health and Nutrition Examination Survey 2011-2012 data from 4318 adults with total vitamin B12, holotranscobalamin (holoTC), and methylmalonic acid (MMA) measurements and positive holoTC subsample weights. Low total vitamin B12 was defined as a level less than 200 pg/mL (148 pmol/L), low holoTC as a level less than 35 pmol/L, and elevated MMA as a level greater than 300 nmol/L. Analyses incorporated survey weights, strata, and primary sampling units.
Low total vitamin B12 was present in 1.7% of adults compared with low holoTC in 4.7% of adults and elevated MMA in 6.5% of adults. Overall, 9.7% of adults had low holoTC or elevated MMA. Among these adults, 60.6% had total vitamin B12 levels greater than 300 pg/mL. In a secondary integrated analysis, 2.2% (95% CI, 1.5%-2.9%) had a 3-marker combined vitamin B12 indicator less than -0.5. Methylmalonic acid-based discordance increased with declining estimated glomerular filtration rate.
Marker-defined low holoTC or elevated MMA was more common than low total vitamin B12. Methylmalonic acid should be interpreted in the context of kidney function.
PMID:
42901726
Bibliographic data and abstract were imported from PubMed on 21 Oct 2026.
Read full publication at:
Please sign in
to see all details.
Advertisement
Stats
- Recommendations n/a n/a positive of 0 vote(s)
- Views 13
- Comments 0