Professors of engineering at the School of Biological and Health Systems at Arizona State University in the USA have found that, at least under laboratory conditions, vitamin B6 restores health to arterial cells damaged by high blood sugars.
In fact, the American research scientists found that vitamin B6 can restore health to the cells that line blood vessels even under extreme diabetic conditions.
The researchers cultured human arterial cells in nutrient media containing normal glucose levels (5.5 mM or 90 mg/dl), a typical glucose level for an untreated diabetic (17.5 mM or about 300 mg/dl), and a glucose level associated with treatment at the emergency room or hospital admissions (30.5 mM or about 550 mg/dl). They added varying concentrations of pyridoxine, also known as B6, to the solutions to see if the vitamin helped the cells overcome the effects of high blood sugar levels.
The Arizona engineers measured the ability of these cells to migrate to heal a tear in an arterial wall, and the ability of these cells to stretch so a blood vessel could be opened to lower blood pressure. Both abilities are often impaired in diabetes. Healthy blood vessels are like rubber hoses in that they can stretch and contract to accommodate changes in blood flow. Diabetic blood vessels are often like pipes in that their walls stay the same no matter how much or how little blood is passing through. They cannot dilate to lower blood pressure, and they cannot constrict to stop bleeding.
The dosage of vitamin B6 that restored arterial function, even when blood glucose readings were a very high 550 mg/dl, was equivalent to the amount received by an adult taking 30 to 50 mg/day of B6 from vitamin supplements. That's more than you get from taking a "complete B" supplement. You would have to take a separate B6 supplement. You should still take the complete vitamin B supplement just to make sure you receive all the vitamin cofactors that work with the pyridoxine your blood vessels need. But this is a very inexpensive way to help lower the risk of a very dangerous health problem, with a supplement that causes no side effects when taken with complete B's.
Kelso BG, Brower JB, Targovnik JH, Caplan MR. Pyridoxine Restores Endothelial Cell Function in High Glucose. Metab Syndr Relat Disord. 2010 Oct 30. [Epub ahead of print]