The metal, which is a constituent of vitamin B12 is____________?A. IronB. MagnesiumC. ZincD. Cobalt 0 0 votesArticle Rating Subscribe LoginNotify of new follow-up commentsnew replies to my comments Label {} [+] Name* Email* Website Label {} [+] Name* Email* Website 0 Comments Oldest Newest Most Voted Inline FeedbacksView all comments