Paradoxical increase of plasma vitamin B12 and folates with disease severity in anorexia nervosa.

Objective: Anorexia nervosa (AN) is a complex disorder involving severe psychological manifestations and multiple organ damage, including liver dysfunction. The primary aim of this study consisted in assessing plasma levels of vitamin B12 and folates with respect to liver function enzymes considering the liver-storage properties of this vitamin.

Method: We recruited 70 restrictive type AN adolescents and the severity of psychopathological traits was assessed using EDI-3 scale. Plasma levels of vitamin B12 , folates, transaminases (AST, ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP) and cholinesterase (CHE) were determined.

Results: About 38.5% of patients displayed vitamin B12 values (H-B12) above the upper range of normal reference; 4.3% of patients had increased values of folates; 20 and 11.4% of patients displayed ALT and AST values above reference limits; none had GGT values above normal range. Albeit low CHE and ALP values were found in 55 and 20% of patients, respectively, a linear correlation with both transaminases was present only for vitamin B12 and folates; furthermore, H-B12 patients had both higher AST and ALT values. EDI- 3 subscores significantly correlated with vitamin B12 and folates plasma values and H-B12 patients displayed EDI-3 higher values.

Discussion: These data suggest that plasma levels of vitamin B12 might be an early marker of liver dysfunction, possibly also related to more severe psychopathological aspects. The identification of patients with higher fasting plasma vitamin B12 levels could therefore lead to earlier and more careful refeeding interventions. Further studies will clarify the potential role of this vitamin in AN clinical practice.