B vitamins exist in different forms, but some of the active forms found in high quality supplements include methylcobalamin (B12), pyridoxal-5-phosphate (B6), and 5-methyltetrahydrofolate (folate) like in Canprev BioActive B Complex. These active forms are readily utilized by the body and may be preferred for better absorption and effectiveness, especially in individuals with certain genetic variations that affect nutrient metabolism.