Correlation between Vitamin B12 and Mental Health in Children and Adolescents: A Systematic Review and Meta-analysis

Tan Y, Zhou L, Gu K, Xie C, Wang Y, Cha L, Wu Y, Wang J, Song X, Chen X, Hu H, Yang Q (2023) Clin Psychopharmacol Neurosci 21(4) 617-633. doi: 10.9758/cpn.22.1040. Epub 2023 Jun 2.

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Abstract:

To conduct the association between vitamin B12 and mental health in children and adolescents. Five databases were searched for observational studies in any language reporting on mental health and vitamin B12 levels or intake in children and adolescents from inception to March 18, 2022. Two authors independently extracted data and assessed study quality. Qualitative and quantitative analysis of data were performed. The review was registered in the PROSPERO database (CRD42022345476).

Fifty six studies containing 37,932 participants were identified in the review.

Vitamin B12 levels were lower in participants with autism spectrum disorders (ASD) (standardized mean difference [SMD], -1.61; 95% confidence interval [95% CI], -2.44 to -0.79; p ＜ 0.001), attention deficit hyperactivity disorders (SMD, -0.39; 95% CI, -0.78 to -0.00; p = 0.049) compared with control group.

Vitamin B12 intake were lower in participants with ASDs (SMD, -0.86; 95% CI, -1.48 to -0.24; p = 0.006) compared with control group, but showed no difference between depression group (SMD, -0.06; 95% CI, -0.15 to 0.03; p = 0.17) and the control group.

Higher vitamin B12 intake were associated with lower risk of depression (odds ratio [OR], 0.79; 95% CI, 0.63-0.98; p = 0.034) and behavioral problems (OR, 0.83; 95% CI, 0.69-0.99; p = 0.04).

The vast majority of included studies supported potential positive influence of vitamin B12 on mental health, and vitamin B12 deficiency may be a reversible cause for some mental health disorders in children and adolescents.

FAB RESEARCH COMMENT:

This new systematic review examined the evidence linking Vitamin B12 to mental health disorders in children and adolescents, and included 56 studies, involving around 38,000 participants.

Results of meta-analyses showed that:

Low Vitamin B12 status is significantly more common in children with Autistic Spectrum Disorders, or ADHD

higher levels of Vitamin B12 are also associated with fewer symptoms of depression, although comparisons of individuals diagnosed with clinical-level depression vs controls did not reach statistical significance.

Vitamin B12 is absolutely essential for healthy brain development and function, as it is needed for the formation of both myelin and red blood cells. Along with with Vitamin B6 and folate, B12 also helps to recycle homocysteine, a toxic byproduct of normal metabolism.

Importantly, mental symptoms are often the first (and sometimes the only) sign of Vitamin B12 deficiency or insufficiency. The symptoms can vary widely between individuals, but a lack of B12 can mimic the symptoms of almost any psychological, psychiatric or neurological disorder.

Even more important is that unless identified and treated, prolonged B12 deficiency can lead to permanent brain and nervous system damage, or even death. (Unfortunately, however, measuring B12 status accurately in practice is not easy, hence cases can be missed even if individuals receive medical attention for their symptoms)

In adults, systematic reviews have already linked B12 deficiency with a wide range of mental health disorders, but this new study is one of the first to combine the available evidence in children.

As B12 is found only in animal foods, vegans (and many vegetarians - or others whose diets are heavily plant-based) need to supplement or use fortified foods. However, deficiencies can also arise from difficulties with absorption, and use of many common medications (including 'antacids', metformin and nitrous oxide in particular).

FURTHER INFORMATION

The following books - written for the general public as well as health professionals - provide an excellent and accessible summmary of the issues surrounding the identification and treatment of B12 deficiency: