Yes! Genetic engineering moves lectin molecules from one species to another. Since lectins are the molecules that interact with our blood types, an OK food can easily become an avoid. Currently, the only way to safely avoid 'GE' foods is to choose organic.
Rather than trying to make a one-size fits all blend, Dr. D'Adamo specially formulated his Polyvite multivitamins for each blood type, giving people the specific vitamins that help their body best.