Is (57Co)Vitamin B12 Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use (57Co)Vitamin B12? Is (57Co)Vitamin B12 safe for nursing mother and child? Does (57Co)Vitamin B12 extracts into breast milk? Does (57Co)Vitamin B12 has any long term or short term side effects on infants? Can (57Co)Vitamin B12 influence milk supply or can (57Co)Vitamin B12 decrease milk supply in lactating mothers?

Information in this record refers to the use of (57Co)Vitamin B12 as a diagnostic agent. Limited data indicate that excretion of radioactivity into breastmilk following (57Co)Vitamin B12 is low and does not require withholding of breastfeeding after diagnostic use. However, to minimize the radiation dose to the infant, some authors suggest that previously saved milk could be substituted for one feeding at about 24 hours after the dose.[1] Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level she may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[2]