The independent and joint associations of vitamin B12 and methylmalonic acid on the risk of mortality in individuals with metabolic dysfunction-associated steatotic liver disease.

In MASLD patients, MMA rather than dietary and serum vitamin B12 was positively associated with all-cause mortality. The joint effect of high levels of MMA and vitamin B12 showed the strongest associations with all-cause and CVD mortality, with a significant interaction with serum folate.