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Cochrane Database of Systematic Reviews

Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency

Overview of attention for article published in Cochrane database of systematic reviews, March 2018
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About this Attention Score

  • In the top 5% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (98th percentile)
  • High Attention Score compared to outputs of the same age and source (94th percentile)

Mentioned by

6 news outlets
1 blog
238 X users
7 Facebook pages
6 Wikipedia pages
1 Google+ user
2 Redditors
4 YouTube creators


122 Dimensions

Readers on

483 Mendeley
Oral vitamin B<sub>12</sub> versus intramuscular vitamin B<sub>12</sub> for vitamin B<sub>12</sub> deficiency
Published in
Cochrane database of systematic reviews, March 2018
DOI 10.1002/14651858.cd004655.pub3
Pubmed ID

Haiyan Wang, Linyi Li, Ling Ling Qin, Yanan Song, Josep Vidal‐Alaball, Tong Hua Liu


Vitamin B12deficiency is common, and the incidence increases with age. Most people with vitamin B12deficiency are treated in primary care with intramuscular (IM) vitamin B12. Doctors may not be prescribing oral vitamin B12formulations because they may be unaware of this option or have concerns regarding its effectiveness. To assess the effects of oral vitamin B12versus intramuscular vitamin B12for vitamin B12deficiency. We searched CENTRAL, MEDLINE, Embase, and LILACS, as well as the WHO ICTRP and ClinicalTrials.gov. The latest search date was 17 July 2017. We applied no language restrictions. We also contacted authors of relevant trials to enquire about other published or unpublished studies and ongoing trials. Randomised controlled trials (RCTs) comparing the effect of oral versus IM vitamin B12for vitamin B12deficiency. We used standard methodological procedures expected by Cochrane. Our primary outcomes were serum vitamin B12levels, clinical signs and symptoms of vitamin B12deficiency, and adverse events. Secondary outcomes were health-related quality of life, acceptability to patients, haemoglobin and mean corpuscular volume, total homocysteine and serum methylmalonic acid levels, and socioeconomic effects. We used GRADE to assess the quality of the evidence for important outcomes. We did not perform meta-analyses due to the small number of included trials and substantial clinical heterogeneity. Three RCTs met our inclusion criteria. The trials randomised 153 participants (74 participants to oral vitamin B12and 79 participants to IM vitamin B12). Treatment duration and follow-up ranged between three and four months. The mean age of participants ranged from 38.6 to 72 years. The treatment frequency and daily dose of vitamin B12in the oral and IM groups varied among trials. Only one trial had low or unclear risk of bias across all domains and outcome measures. Two trials reported data for serum vitamin B12levels. The overall quality of evidence for this outcome was low due to serious imprecision (low number of trials and participants). In two trials employing 1000 μg/day oral vitamin B12, there was no clinically relevant difference in vitamin B12levels when compared with IM vitamin B12. One trial used 2000 μg/day vitamin B12and demonstrated a mean difference of 680 pg/mL (95% confidence interval 392.7 to 967.3) in favour of oral vitamin B12. Two trials reported data on adverse events (very low-quality evidence due to risk of performance bias, detection bias, and serious imprecision). One trial stated that no treatment-related adverse events were seen in both the oral and IM vitamin B12groups. One trial reported that 2 of 30 participants (6.7%) in the oral vitamin B12group left the trial early due to adverse events. Orally taken vitamin B12showed lower treatment-associated costs than IM vitamin B12in one trial (low-quality evidence due to serious imprecision). No trial reported on clinical signs and symptoms of vitamin B12deficiency, health-related quality of life, or acceptability of the treatment scheme. Low quality evidence shows oral and IM vitamin B12having similar effects in terms of normalising serum vitamin B12levels, but oral treatment costs less. We found very low-quality evidence that oral vitamin B12appears as safe as IM vitamin B12. Further trials should conduct better randomisation and blinding procedures, recruit more participants, and provide adequate reporting. Future trials should also measure important outcomes such as the clinical signs and symptoms of vitamin B12deficiency, health related-quality of life, socioeconomic effects, and report adverse events adequately, preferably in a primary care setting.

X Demographics

X Demographics

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Mendeley readers

Mendeley readers

The data shown below were compiled from readership statistics for 483 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 483 100%

Demographic breakdown

Readers by professional status Count As %
Student > Master 69 14%
Student > Bachelor 56 12%
Researcher 42 9%
Student > Ph. D. Student 29 6%
Other 24 5%
Other 79 16%
Unknown 184 38%
Readers by discipline Count As %
Medicine and Dentistry 124 26%
Nursing and Health Professions 42 9%
Pharmacology, Toxicology and Pharmaceutical Science 19 4%
Biochemistry, Genetics and Molecular Biology 17 4%
Psychology 15 3%
Other 64 13%
Unknown 202 42%
Attention Score in Context

Attention Score in Context

This research output has an Altmetric Attention Score of 221. 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 17 April 2024.
All research outputs
of 26,386,754 outputs
Outputs from Cochrane database of systematic reviews
of 13,215 outputs
Outputs of similar age
of 356,199 outputs
Outputs of similar age from Cochrane database of systematic reviews
of 215 outputs
Altmetric has tracked 26,386,754 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 99th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 13,215 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 35.7. This one has done particularly well, scoring higher than 97% 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 356,199 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 98% of its contemporaries.
We're also able to compare this research output to 215 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 94% of its contemporaries.