Primary Research · 2014
The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12
Pawlak et al. · European Journal of Clinical Nutrition, 2014
Key finding
Systematic review finding B12 deficiency prevalence of 62% in pregnant vegetarian women, 86% in elderly vegetarians, 41% in adolescents.
Abstract
PubMed · PMID 23942765 →INTRODUCTION: White matter injury and abnormal maturation are thought to be major contributors to the neurodevelopmental disabilities observed in children and adolescents who were born preterm. Early detection of abnormal white matter maturation is important in the design of preventive, protective, and rehabilitative strategies for the management of the preterm infant. Diffusion-weighted magnetic resonance imaging (d-MRI) has become a valuable tool in assessing white matter maturation and injury in survivors of preterm birth. In this review, we aim to (1) describe the basic concepts of d-MRI; (2) evaluate the methods that are currently used to analyse d-MRI; (3) discuss neuroimaging correlates of preterm brain injury observed at term corrected age; during infancy, adolescence and in early adulthood; and (4) explore the relationship between d-MRI measures and subsequent neurodevelopmental performance. METHODS: References for this review were identified through searches of PubMed and Google Scholar before March 2013. RESULTS: The impact of premature birth on cerebral white matter can be observed from term-equivalent age through to adulthood. Disruptions to white matter development, identified by d-MRI, are related to diminished performance in functional domains including motor performance, cognition and behaviour in early childhood and in later life. CONCLUSION: d-MRI is an effective tool for investigating preterm white matter injury. With advances in image acquisition and analysis approaches, d-MRI has the potential to be a biomarker of subsequent outcome and to evaluate efficacy of clinical interventions in this population.
Abstract sourced from PubMed, a database of the U.S. National Library of Medicine. Displayed in the authors’ own words for context; our critique is in the sections below.
Read the full paper
Cited in 3 guides
Guide
Do You Need a Multivitamin? Clinical Evidence 2026
Most adults take multivitamins as nutritional insurance — but 700,000-person studies show near-zero mortality benefit. Learn when one helps and when to target instead.
Guide
How to Build a Supplement Stack (2026) — Evidence-Based
Skip the influencer hauls. Learn a step-by-step, evidence-based method to build a supplement stack that fits your goals — without wasting money.
Guide
Vitamin B12 Guide 2026: Which Form & Dose You Need
Find out if you’re actually B12 deficient — and why standard tests miss it. Covers methylcobalamin vs cyanocobalamin, dosing, and the MMA test.
How to read a study like this
The same questions worth asking about any research paper, not just this one. Worth a minute even if you trust the grade.
Who was studied, and do you resemble them?
Supplement effects often depend on baseline status. Vitamin D helps people who are deficient; iron helps people who are anemic. A result in people unlike you may not apply to you.
What was measured, and does it matter in daily life?
A study that shows a blood marker moved isn't the same as a study that shows people felt or functioned better. Ask what the outcome means in practice.
How large was the effect — not just whether it was significant.
'Statistically significant' only means the effect is unlikely to be zero. It doesn't tell you the effect is large enough to notice. Look for effect sizes, not just p-values.
Who paid for the trial, and what did they stand to gain?
Industry-funded trials are several times more likely to report positive results than independent ones. It's not usually fraud — it's subtle design and reporting choices. Weight accordingly.
Has anyone else replicated this?
Single positive trials are hypotheses. Replication by independent groups is what turns a hypothesis into reliable evidence. If the only positive trial is the one you're reading, wait.
Does the dose in the trial match what's being sold?
Supplement marketing routinely cites trials that used 5–10× the dose in the product. If the effective dose was 2 g/day and the capsule has 200 mg, expect roughly no effect.
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