Nicola E. Brasch and Derek S. Damron of Kent State University and colleagues report the synthesis of the first vanadium-vitamin B-12 bioconjugates (Chem. Commun., DOI: 10.1039/b806598e). These complexes could lead to novel orally active therapeutics for lowering high blood glucose levels associated with diabetes, the researchers suggest. Diabetics who must take insulin to regulate carbohydrate and lipid metabolism are often reluctant to inject the protein hormone several times per day, and even when they take their injections, they may still experience swings in blood sugar levels. Researchers are therefore trying to develop alternative oral treatments to work around these problems. Over the past decade, vanadium salts have shown promise in lab studies, but toxicity due to their poor absorption in the body became evident during clinical trials with type 1 and type 2 diabetics. Brasch's team reasoned that attaching a vanadium complex to a common vitamin should improve absorption by taking advantage of the body's vitamin uptake mechanisms. With this approach other B–12 conjugates have been successfully developed for medical uses, including chemotherapy and imaging. The researchers combined sodium metavanadate with a derivative of vitamin B–12 to make a mixture of mono and bis conjugates. The mixture was more effective at reducing glucose levels in diabetic rats than sodium metavanadate alone, they found.