[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4196321/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950042/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4918681/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645155/
[5] https://essentia.com.br/deficiencia-de-vitamina-b12-uma-epidemia-silenciosa-com-graves-consequencias/