We read with much interest the article published by Hvas et al.1 It reaches very interesting conclusions and deserves some careful considerations.
The follow-up study of individuals with slightly increased levels of plasma methylmalonic acid (P-MMA) during a period of up to 3.9 years, with no evidence of clinical manifestations of vitamin B12 deficiency, supports the thesis of its doubtful clinical significance as a marker for vitamin B12 deficiency.2,3
Aguirre C, Barreiro G. Methylmalonic Acid and Clinical Practice. Arch Intern Med. 2002;162(1):102-103. doi: