Luciana Hannibal, Vegard Lysne, Anne-Lise Bjørke-Monsen, Sidney Behringer, Sarah C. Grünert, Ute Spiekerkoetter, Donald W. Jacobsen, Henk J. Blom
Abstract
Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MCM). Deficiency of Cbl, whether nutritional or due to inborn errors of Cbl metabolism, inactivate MS and MCM leading to the accumulation of homocysteine (Hcy) and methylmalonic acid (MMA), respectively. In conjunction with total B12 and its bioactive protein-bound form, holo-transcobalamin (holo-TC), Hcy, and MMA are the preferred serum biomarkers utilized to determine B12 status. Clinically, vitamin B12 deficiency leads to neurological deterioration and megaloblastic anemia, and, if left untreated, to death. Subclinical vitamin B12 deficiency (usually defined as a total serum B12 of <200 pmol/L) presents asymptomatically or with rather subtle generic symptoms that oftentimes are mistakenly ascribed to unrelated disorders. Numerous studies have now established that serum vitamin B12 has limited diagnostic value as a stand-alone marker. Low serum levels of vitamin B12 not always represent deficiency, and likewise, severe functional deficiency of the micronutrient has been documented in the presence of normal and even high levels of serum vitamin B12. This review discusses the usefulness and limitations of current biomarkers of B12 status in newborn screening, infant and adult diagnostics, the algorithms utilized to diagnose B12 deficiency and unusual findings of vitamin B12 status in various human disorders.
Pharmacology, Toxicology and Pharmaceutical Science
11
3%
Other
38
9%
Unknown
137
34%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 43. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 10 September 2024.
All research outputs
#1,039,361
of 26,599,665 outputs
Outputs from Frontiers in Molecular Biosciences
#40
of 4,861 outputs
Outputs of similar age
#18,583
of 367,279 outputs
Outputs of similar age from Frontiers in Molecular Biosciences
#1
of 23 outputs
Altmetric has tracked 26,599,665 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 96th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 4,861 research outputs from this source. They receive a mean Attention Score of 3.7. This one has done particularly well, scoring higher than 99% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 367,279 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 94% of its contemporaries.
We're also able to compare this research output to 23 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 95% of its contemporaries.
