Thiamin (Vitamin B1) Levels in Eating Disorder Adolescent Patients

Vitamin B1 (Thiamine) is a water soluble essential nutrient; it is synthesized by a variety of plants and microorganisms. Since animals usually cannot synthesis it, humans must be supplied with exogenous vitamin B1 in the diet. The human storage of thiamine is small- about 30mg, an intake of 1-2 mg a day is needed to maintain this pool. Deficiency might occur when the vitamin is depleted from the diet in a short period. Vitamin B1 has a role in energy metabolism and main biosynthetic pathways. Low thiamine causes illnesses in the central and peripheral nervous systems as well as affecting the heart and gastrointestinal systems.

Deficiency may occur from malnutrition of different mechanisms such as alcoholism, lack in diet and recently secondary to anti-obesity surgery and few case reports described eating disorders as the reason for developing deficiency causing neuropathy, (1,2) and encephalopathy (3,4,5).

One of the presentations of thiamine deficiency is peripheral neuropathy mimicking Guillain-Barre syndrome, and administering the lacking vitamin improves the symptoms.

One study examined the prevalence of vitamin B1 deficiency in adult anorexia nervosa patients (6) by measurement of the activation of the enzyme erythrocyte transketolase following addition of thiamin pyrophosphate and comparing them to control of blood donors. This study found significant lower levels of vitamin B1 in the anorectic patient compared to the controls.

Rational of the study:

The investigators assume that these few cases described of overt neurologic impairment due to vitamin B1 deficiency because of distorted eating are just the "tip of the iceberg" and more eating disorders patients lack thiamine, that may have neuropsychiatric effect on the illness and identifying and treating the shortage may improve the symptoms of the disorder and maybe even the distorted thoughts that are fundamental in eating disorders.