The effects of vitamin B12 supplementation on metabolic profile of patients with non-alcoholic fatty liver disease: a randomized controlled trial

The present study is the first effort to evaluate the effects of vitamin B12 supplementation on the serum level of liver enzymes, homocysteine, grade of hepatic steatosis, and metabolic profiles in patients with non-alcoholic fatty liver disease (NAFLD). Forty patients with NAFLD were enrolled in a double-blind placebo-controlled trial to receive either one oral tablet of vitamin B12 (1000 µg cyanocobalamin) or a placebo per day for 12 weeks. We investigated serum levels of homocysteine, aminotransferases, fasting blood glucose (FBG), lipids, malondialdehyde (MDA), and homeostasis model assessment of insulin resistance (HOMA-IR). The grade of liver steatosis and fibrosis was measured by real-time 2-dimensional shear wave elastography. Vitamin B12 supplementation significantly decreased serum levels of homocysteine compared to placebo (medians: - 2.1 vs. - 0.003 µmol/l; P = 0.038). Although serum alanine transaminase (ALT) in the vitamin B12 group decreased significantly, this change did not reach a significant level compared to the placebo group (medians: - 7.0 vs. 0.0 IU/l; P > 0.05). Despite the significant within-group decrease in FBG, MDA, and liver steatosis in the vitamin B12 group, between-group comparisons did not reveal any significant difference. Vitamin B12 supplementation might decrease serum levels of homocysteine in patients with NAFLD. The fasting blood glucose and serum levels of MDA were significantly improved in the trial group who received vitamin B12. However, these changes did not reach a significant level compared to the placebo group. In this respect, further studies with larger sample sizes, different doses, and types of vitamin B12 will reveal additional evidence.Trial Registration: At  http://irct.ir/  as IRCT20120718010333N5 on December 25, 2019.