Thanks for that goji.
As this was May 2008 I have looked for updates from Warwick University but cannot find any.
Would be interested if anyone has found any further research and it included therapeutic dosage.
There is also this article dated Friday 2nd april 2010 but which is actually from January 12th 2009:
High-Dose Thiamine Supplementation Could Reverse Microalbuminuria in Diabetes Patients.
There is an RDA mentioned in the Wikepaedia article. However, any supplement or dosage should be discussed with your GP as there may be interactions with other medications.
Professor Thornalley explained: "There will of course be clinical trials to investigate further the findings we have made using an experimental model of diabetes. However, given the continuing toll of heart disease in diabetic patients, and the emerging benefits of thiamine therapy for diabetics suffering from kidney disease - as reported by our research group last year - I would strongly suggest that those with diabetes are given thiamine supplements."