Effects of low-dose B vitamins plus betaine supplementation on lowering homocysteine concentrations among Chinese adults with hyperhomocysteinemia: a randomized, double-blind, controlled preliminary clinical trial

PURPOSE: To test the hypothesis that daily supplementation with low-dose B vitamins plus betaine could significantly reduce plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia and free from background mandatory folic acid fortification. METHODS: One hundred apparently healthy adults aged 18–65 years with hyperhomocysteinemia were recruited in South China from July 2019 to June 2021. They were randomly assigned to either the supplement group (daily supplementation: 400 μg folic acid, 8 mg vitamin B(6), 6.4 μg vitamin B(12) and 1 g betaine) or the placebo group for 12 weeks. Fasting venous blood was collected at baseline, week 4 and week 12 to determine the concentrations of homocysteine, folate, vitamin B(12) and betaine. Generalized estimation equations were used for statistical analysis. RESULTS: Statistically significant increments in blood concentrations of folate, vitamin B(12) and betaine after the intervention in the supplement group indicated good participant compliance. At baseline, there were no significant differences in plasma homocysteine concentration between the two groups (P = 0.265). After 12-week supplementation, compared with the placebo group, there was a significant reduction in plasma homocysteine concentrations in the supplement group (mean group difference − 3.87; covariate-adjusted P = 0.012; reduction rate 10.1%; covariate-adjusted P < 0.001). In the supplement group, the decreased concentration of plasma homocysteine was associated with increments of blood concentrations of both folate (β = –1.680, P = 0.004) and betaine (β = –1.421, P = 0.020) after 12 weeks of supplementation. CONCLUSIONS: Daily supplementation with low-dose B vitamins plus betaine for 12 weeks effectively decreased plasma homocysteine concentrations in Chinese adults with hyperhomocysteinemia. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT03720249 on October 25, 2018. Website:https://clinicaltrials.gov/ct2/show/NCT03720249 . SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00394-023-03087-y.