Methylation and sulfuration are complex processes and assessing them in clinical practice take skill, knowledge, and consideration of multiple genes and other factors. In this interview with Dr Fitzgerald, Dr David Quig discusses the assessment of methylation in clinical practice.

What you’ll learn in this podcast:

  1. The importance of considering multiple genes for a given metabolic process
  2. Understanding which patients are the best candidates for methylation investigation
  3. How to work with patients to explain that MTHFR status is just one data point in a much bigger, more complex picture
  4. The importance of looking at s-adenosylmethionine and s-adenosylhomocysteine
  5. The dangers of compromised collection at labs and draw centers
  6. The methylation profile available from Doctor’s Data, which includes methionine, cysteine, S-adenosylmethionine, S-adenosylhomocysteine, homocysteine, and cystathionine
  7. Why Dr. Quig doesn’t recommend supplementing with SAM
  8. The dangers of supplementing with SAM long-term
  9. How people tolerate 5-methyltetrahydrofolate differently
  10. The one benefit—and the many limits—of synthetic folic acid
  11. Understanding overmethylation / overmethylators
  12. Interventions for high homocysteine


Dr David Quig Ph.D, MPH, Vice President of Scientific Support for Doctor’s Data

David Quig, Ph.D. David received his BS and MS degrees in Human Nutrition from Virginia Tech and a Ph.D. in Nutritional Biochemistry from the University of Illinois.

After a five year stint as a Research Associate studying lipid biochemistry and cardiovascular disease at Cornell University, he was a Senior Cardiovascular Pharmacologist for seven years. For the past 23 years, David has been the Vice President of Scientific Support for Doctor’s Data, Inc.

He has focused on toxic elements, methylation and amino acid metabolism, the applied biochemistry of endogenous detoxification, and the influence of the gastrointestinal metabolome on overall health.