Participants will be randomized to receive either betaine or placebo for the first 2 month arm of the study. Following 2 months of treatment and 2 months of washout, each participant will cross over to the other arm of the study. The other arm will consist of the participant being on 2 months of treatment of whatever they were not taking in the first arm (betaine vs. placebo). Neither the study staff nor the participant will know whether the participant is taking betaine for the first or second arm of the study, or the placebo for the first or second arm of the study. Only the pharmacy will know this.