title: On the biosynthesis of heme and vitamin B 12  from ( ,  - 14 C 2 )uroporphyrinogen 3.
mesh_terms: D002247:Carbon Isotopes; D006418:Heme / Q000096:biosynthesis*; D011166:Porphyrins / Q000378:metabolism*; D014805:Vitamin B 12 / Q000096:biosynthesis*
chemical_list: D002247:Carbon Isotopes; D011166:Porphyrins; D006418:Heme; D014805:Vitamin B 12