Methylation is a critical component of many biochemical reactions in the body and as such, is a key determinant of optimal function and health. However, the complex and interrelated nature of methylation pathways and the debate surrounding clinical applications of treatments that affect methylation can make it difficult for clinicians to know what to tell their patients. This course will explore the biochemical pathways that rely on methylation, the problems that can result from genetic and environmental deficiencies that affect methylation, and the best strategies for assessing and treating these deficiencies using vitamins and supplements.