There are HUGE differences in supplements. Quality can vary tremendously. The vast majority of supplements on the market are synthetic, DrVitamins offers a better metabolized whole food or natural supplement that often gives a better result. This is one reason why nearly all of our products are whole food extracts and concentrates. ALL of the nutrition is there. Dr. Theodore Cole, medical advisor, uses these products at the Cole Center for Healing and Cincinnati Hyperbarics everyday.