Functional Vitamin B12 Deficiency in Sleep Disorders in Children

It has been known for some time that an absolute deficiency in vitamin B12 is often associated with sleep disorders in children. The mechanism for the sleep disorders, though, is not generally stated. We have identified a cohort of children, who suffered from long term sleep disorders, who were characterized by elevated serum vitamin B12 levels. Retrospective Organic Acid Analysis of the urine of the children identified many markers of functional vitamin B12 deficiency, despite the elevated serum B12. As such the children may have paradoxical B12 in which serum levels of vitamin B12 were normal or elevated, however they had elevated markers of functional vitamin B12 deficiency. This functional vitamin B12 deficiency appeared to be the result of functional vitamin B2 deficiency. The mechanism is discussed. Effective treatment required resolution of the functional vitamin B2 deficiency as well as high dose vitamin B12 administration.