Could the Glycine/Serine ratio could tell us anything about whether a person is over/undermethlyated? I don't think it could be used all by itself, but along with other factors it might give evidence for a person to figure out if they are an over or under methylator. Here are the NutrEval results for me and my husband. The ratios go along with what I have suspected to be our methylation type. I think the angle of the red line is more important than the ratio numbers. A person could have a high or low ratio and have normal methylation, since so many factors are involved, but if a person has reason to believe that their methylation is not normal, the ratio could give a clue because glycine is used to keep SAMe levels from getting too high, and the glycine/serine ratio affects the direction of the SHMT enzyme which affects the availability of 5, 10 methyleneTHF, which is needed for MTHFR and for thymidlyate synthesis.