Thiamin (Vitamin B1) Levels in Eating Disorder Adolescent Patients

Methods:

In Assaf Harofe medical center over 50 adolescents (mainly girls) aged 10-18 years are treated annually for eating disorders by a multidisciplinary team. Their nutritional and medical condition is assessed also by blood analysis routinely. The investigators are planning to check thiamine status in eating disorders female patients in different stages of treatment, comparing them with age and sex matched controls that do not have eating disorders problems. The control group will be recruited from patient treated in the outpatient day hospital and have blood tested anyhow that don't suffer from eating, metabolic, nutritional or gastrointestinal disorders.

The researchers will look for correlation between different types of eating disorders, nutritional state, treatment progress and levels of vitamin B1.

Thiamin will be determined in whole blood using High-Performance Liquid Chromatography (HPLC) that is superior to the previous method as described above, determining thiamin diphosphate; the physiologically active form of vitamin B1 accurately.

Sample size: A previous study on thiamine concentration in 50 healthy French volunteers found a standard deviation (SD) of 15 nmol/l (7). 17 patients in each group were required in order to detect a 15 nmol/l difference in mean thiamine levels with a power of 80% and Alfa of 0.05. In order to overcome a possibly higher SD and to allow for subgroup analysis , we decided to recruit 30 patients for each group.