House and Fletcher (2003) also observed greater plasma concentrations of MMA at 1.48 vs. 0.43 µM in postweaning piglets fed dietary cyanocobalamin at 0 and 140 µg/kg, respectively. Thus, although the relevance of plasma MMA as an indicator of B12 adequacy remains to be established in pig species (House and Fletcher, 2003), the present results are all the more important because S−P− piglets are representative, as stated earlier, of classical husbandry conditions and levels of dietary supplements of both folic acid and B12 in dams and postweaning piglets in the feed industry (BASF, 2001).