Check out Life Extension - Vitamin C and Bio-Quercetin Phytosome Vegetarian Tablet, featuring 1000mg of vitamin C with highly absorbable quercetin. Supporting various biological functions, the vitamin C within is great for supplementing the immune system and provides antioxidant support. In addition, the Bio-Quercetin doubles down to help the immune system and is up to 50 times more bioavailable than traditional quercetin.