. Conclusions
A survey of naturally occurring and high Vitamin B12-containing plant-derived food sources showed that nori, which is formed into a sheet and dried, is the most suitable Vitamin B12 source for vegetarians presently available. Consumption of approximately 4 g of dried purple laver (Vitamin B12 content: 77.6 μg /100 g dry weight) supplies the RDA of 2.4 μg/day. In Japan, several sheets of nori (9 × 3 cm2; approximately 0.3 g each) are often served for breakfast. A large amount of nori can be consumed as certain forms of sushi (vinegared rice rolled in nori). In particular, hand-rolled sushi made by wrapping rice and fillings with nori is easy to prepare and facilitates the consumption of a large amount of nori. When dried purple laver was treated by toasting until the laver’s color changed from purple to green, the toasting treatment did not affect the Vitamin B12 contents [
57]. Dried purple lavers could also be a suitable food item for integration in Italian, French, and other forms of western cuisine. Dried purple laver is also a rich source of iron and
n-3 polyunsaturated fatty acids (
Figure 4). Dried purple laver is a natural plant product; therefore, it is suitable for most vegetarian groups.