Here is some info on different types of seaweed with B vitamins.
Arame is the black spaghetti-like seaweed growing around rocks below the coasts of Japan. Iron, iodine, potassium, and vitamins A and B are elevated in arame. Low in sodium, it is suitable for hypertension sufferers. Arame should be boiled for ten minutes and then added to stir-fries, stews, and vegetables. They taste good with rice and salads.
Dulse (purple-red branches) grows in the North Atlantic and Northwest Pacific. The Irish enjoy this salty chewy snack. It is rich in vitamin B6 and B12 and iron. Soak dulse, shred it, and add it to sandwiches and salads. It is also good when roasted dry and crushed over salads or other dishes.
Alaria’s brown yellow branches are found along the coastal waters of North America. They are rich in vitamin B and provide the daily need for calcium. The delicate smooth flavor mixes well with soups, seafood, and stews, but it requires thorough cooking. Alaria makes a nice chewy snack.