Co-Defense is a multivitamin uniquely formulated for patients who take macular degeneration supplements based upon the National Eye Institute's Age Related Eye Disease Study. Co-Defense removes Vitamin A, C, E, Zinc and Copper - nutrients that already exist in high amounts in VisiVite and other macular degeneration supplements. Compared with other multivitamins, Co-Defense contains twice the levels of water soluble B vitamins and triple the amount of Lycopene, nutrients that are of greater importance as we age. Why does this supplement use Vitamin D-2 rather than D-3? While absorption of D3 is greater than D2, VisiVite uses D2 in its Co-Defense formula because it is 100% vegetarian and vegan. D3 is extracted from sheep's wool fat. People who have difficulty swallowing should take Co-Defense Minis.