Research paper
Studies of biomarker responses to intervention with vitamin B-12: a systematic review of randomized controlled trials.
Study answer
What this study found
Oral vitamin B-12 supplementation reliably improved biomarkers of vitamin B-12 status. Serum/plasma total vitamin B-12 increased across 8 RCTs (WMD 185 pmol/L; 95% CI 107, 263; n = 506; P < 0.00001), while methylmalonic acid decreased (WMD 20.28 lmol/L; 95% CI 20.35, 20.22; n = 186; P < 0.00001) and total homocysteine decreased (WMD 23.3 lmol/L; 95% CI 24.5, 22.2; n = 282; P < 0.00001). Holotranscobalamin could not be evaluated reliably because it was measured in only one study. The authors concluded that serum/plasma total vitamin B-12, methylmalonic acid, and total homocysteine are…
- Study & population
- Systematic review of randomized controlled trials in humans, totaling 506 participants across 8 studies.
- Intervention
- Oral vitamin B-12 supplementation was evaluated across 8 randomized controlled trials, using cyanocobalamin or methylcobalamin delivered as capsules, added to milk, or food-based delivery.
- Key limitation
- The evidence base was small and heterogeneous, with varying doses, formulations, and study durations across the trials.
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Open PDFOriginal abstract
BACKGROUND Mild vitamin B-12 deficiency is common among older adults, but evidence for setting dietary recommendations is limited because most studies have administered vitamin B-12 via nonoral routes or at doses several hundred times higher than cur…