water-soluble vitamin nutraceutical B vitamin Any of the group of eight water-soluble vitamins originally thought to be a single compound (vitamin B) that play important roles in cell metabolism. The group comprises vitamin B1, B2, B3, B5, B6, B7, B9, and B12. (Around 20 other compounds were once thought to be B vitamins but are no longer classified as such.) B vitamins B-group vitamin B-group vitamins CHEBI:75769 CiteXplore:22743781 CiteXplore:23093174 CiteXplore:23238962 CiteXplore:23449527 CiteXplore:23462586 CiteXplore:23690582 Wikipedia:B_vitamin chebi_ontology vitamin B