Phosphorus iscritical for life and anindispensable element for biologically occurring organic molecules such asDNA, ATP, and phosphoproteomes. Butafosfan isasynthetically produced organic phosphorous (phosphonic acid) compound that contains 17.3% phosphorus. Itdoes not belong tothe group ofbiologically occurring organic phosphorous compounds. Butafosfan has been used inmany animal species asametabolic stimulant interfering with energy metabolism. Vitamin B12 (VB12) isaunique cobalt-containing vitamin. Itfunctions asacofactor for the enzymes methionine synthase and methyl-malonyl-CoA mutase. Itis necessary for theconversion ofpropionate into succinyl-CoA inruminants. Acombination ofbutafosfan and VB12 (iBC) has been available for veterinary use since 1958 and the first publication appeared inthe 1970s incows. However, thefirst molecular biological studies about its mode ofaction appeared inearly 2000s. Recent studies revealed that iBC has significant effects oncarbohydrate and lipid metabolism. Investigations between 1970 and 1994 focused mainly oncows atrisk ofmetabolic and reproductive disease inthe dry period. Studies asof 2000 investigated its efficacy for the prevention and treatment ofsubclinical and secondary ketosis, adjunctive/supportive therapy for displaced abomasum operation, milk fever, improvement ofpostoperative rumen activity, uterus involution, and mastitis intransition dairy cows.