Reply to: "B vitamins for NASH: Use methylcobalamin, not cyanocobalamin"

We appreciate the letter by Dr. Spence advocating the use of methylcobalamin or hydroxycobalamin rather than the cyanocobalamin form of vitamin B12 (B12) in future clinical trials investigating the efficacy of B vitamins to prevent or treat NASH.1 This is similar to the concern that he raised previously regarding studies that employed B12 for the prevention of stroke.3,4 Although several large trials previously showed no benefit of folate and/or B vitamins (B6 and B12) in reducing cardiovascular events,4 reanalysis of data from one of them (the VISP trial) showed there was a 34% reduction in stroke/myocardial infarction events over 2 years when patients with impaired renal function were excluded.