I just reviewed my blood work with my PCP and my B-12 was 1223 with the range between 243-894. She felt that this might contribute to my confusion and lethargy. I checked my senior multi vitamin and found the B-12 to be 24 mcg or 417% DV. On the other hand, adult multi vitamins have 6 mcg or 100% DV of Vitamin B-12. Going back to my adult multi and hope I see a difference.