I cannot speak for dogs or animals with health conditions. My cat loved dry seaweed sheets but it wasn't used as a substitute to medicine. He enjoyed the olive oil as it helped him clean his fur and keep it shiny. It was more of a snack or treat more than anything else. I wonder if you may need to be careful because of the sodium fresh seaweed can have. Maybe ask the vet about the sodium.
Is there such a thing as special made seaweed from the pet store?
edit: I did a quick internet search and seaweed apparently does have substantial amounts of b12 and it says 1 nori sheet has 80% daily value for human I was picturing 1 small sheet room the snack packages and that's so hard to believe because it tastes so papery but I guess Google says
