Roles and sources of B vitamins in the marine ecosystem

As coenzymes, B vitamins have long been studied by marine researchers. Numerous studies have been conducted on the regulation of phytoplankton communities and algal–bacterial symbiosis. However, the key role of B vitamins in marine ecosystems has not received much attention. Through documents retrieval and genetic database analysis, we concluded the sources of vitamin B1, B2, B6, B7, and B12 in the ocean and proposed their roles in marine ecosystem. Our review analysis demonstrated that producers and consumers of B vitamins are widespread in the ocean, and phytoplankton biomass and community structure are highly responsive to B vitamins. Unfortunately, the B vitamins concentration in seawater is extremely low and has been measured in very few sea areas. We have also shown that marine fish suffer from a wide variety of B vitamin deficiency symptoms when lacking sufficient B vitamins, suggesting that vitamin B restrictions are important for marine fish. On the other hand, fish provides many micronutrients that affect human health, especially for people whose primary diet is fish. We believe that B vitamins in the ocean affect marine ecosystems and fishery resources and, in turn, human health through a bottom-up approach. There are too many unknowns about the role of B vitamins in marine ecosystems, so we recommend more research on the distribution, function, and transfer of B vitamins in the ocean, as well as their effect on fishery resources.