Up to 25 percent of people may have a vitamin B12 deficiency.
Difficulties with thinking and memory can be symptomatic of a deficiency in vitamin B12, research suggests.
People low in vitamin B12 can report having a worse memory for both ideas and events.
Low levels of vitamin B12 may also contribute to brain shrinkage and has even been linked to depression.
Vitamin B12 is critical for the body’s production of red blood cells and for keeping the nervous system healthy.
Other, common signs of vitamin B12 deficiency include experiencing muscle weakness, feeling tired, and being constipated.
Vitamin B12 deficiency is easy to rectify with supplements or by dietary changes.
Vitamin B12 levels can be boosted through supplementation or by eating foods such as dairy, liver, salmon and eggs.
A study of 3,156 children in Columbia has found that those who are deficient in vitamin B12 were twice as likely to repeat a grade.
They were also at double the risk of being absent from school.
The children, aged 5-12, were all tested for various nutritional markers, including B12, folate, zinc and vitamin A.
Fully 15 percent were marginally deficient in vitamin B12 and it was the only deficiency linked to repeating a grade at school.
Dr Eduardo Villamor, who led the study, said:
“Vitamin B12 is necessary for adequate brain development.
Deficiency very early in life or in old age has been linked to cognitive and behavioral problems, but it was not known whether it could be related to academic difficulties during school age.
Grade repetition and school absenteeism are important outcomes because they predict school dropout and impair children’s options for educational advancement and development.”
People who may have difficulty getting enough vitamin B12 include vegetarians, older people and those with some digestive disorders, such as Crohn’s disease.
The study was published in The Journal of Nutrition (Duong et al., 2015).
