Flavonoids may help strengthen weakened capillaries, possibly by protecting collagen, one of the most important components of capillary walls.
150 mg daily. Proanthocyanidins, flavonoids extracted from grape seeds, have been shown to increase capillary strength in people with hypertension and diabetes.
Treat deficiency with up to 1 gram daily. In cases of deficiency, vitamin C has been shown to increase capillary strength, in seniors and people with diabetes in particular.