Asthma, allergy, and responses to methyl donor supplements and nutrients  Sunita Sharma, MD, MPH, Augusto Litonjua, MD, MPH  Journal of Allergy and Clinical Immunology  Volume 133, Issue 5, Pages 1246-1254 (May 2014) DOI: 10.1016/j.jaci.2013.10.039 Copyright © 2013 American Academy of Allergy, Asthma & Immunology Terms and Conditions

Fig 1 Simplified diagram of the one-carbon metabolic pathway. The figure demonstrates where dietary methyl donors, identified in red, are involved in the one-carbon metabolic pathway and how they influence DNA methylation. DNA methylation depends on the availability of methyl groups from S-adenosyl-methionine, which is derived from methionine. This figure highlights the connection between folate, choline, methionine, betaine, and vitamins B2, B6, and B12 on DNA methylation. The pathways intersect at the formation of methionine from homocysteine. Journal of Allergy and Clinical Immunology 2014 133, 1246-1254DOI: (10.1016/j.jaci.2013.10.039) Copyright © 2013 American Academy of Allergy, Asthma & Immunology Terms and Conditions