Measurement and evaluation of thiamine concentrations in the blood of Australians who have a history of Diagnostic and Statistical Manual Fourth Edition(DSM IV) alcohol dependence or abuse, after 20 years of supplementing flour with thiamine.

This study is measuring thiamine (vitamin B1) levels in the blood of Australians who have had alcohol-related driving offences. Thiamine deficiency is common in people who drink heavily and can cause serious brain damage. Researchers want to find out whether Australia's policy of adding thiamine to flour — which has been in place for 20 years — has successfully prevented thiamine deficiency in this high-risk group. You may be eligible if: - You are between 18 and 65 years old - You have been referred to a Driver Assessment Clinic in South Australia because of multiple drink-driving offences - You meet criteria for an alcohol use disorder (DSM-IV criteria) - You are able to provide informed consent You may NOT be eligible if: - You have had stomach, bowel, or weight loss surgery - You have had chronic vomiting or diarrhoea due to certain conditions - You have had certain cancers or blood disorders - You are on dialysis for kidney disease - You have Crohn's disease or other conditions that affect magnesium levels Talk to your doctor about whether this trial might be right for you.