Hydroxocobalamin acetate is an injectable naturally occurring form of vitamin B12 with a favorable adverse effect profile, used as a dietary supplement in the treatment of vitamin B12 deficiency including pernicious anemia[1][2]. The cobalt atom of hydroxocobalamin binds cyanide and nitric oxide (NO) and hydroxocobalamin attenuates vascular responses to NO in vitro[3].
[1]. Cheungpasitporn W, et al. High-dose hydroxocobalamin for vasoplegic syndrome causing false blood leak alarm. Clin Kidney J. 2017 Jun;10(3):357-362. [2]. Wang H, et al. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev. 2018 Mar 15;3:CD004655. [3]. Greenberg SS, et al. Hydroxocobalamin (vitamin B12a) prevents and reverses endotoxin-induced hypotension and mortality in rodents: role of nitric oxide. J Pharmacol Exp Ther. 1995 Apr;273(1):257-65.