Methyl-Guard PlusVarious conditions and stressors can have an adverse impact on the bodys methylation cycle. Nutrient deficiencies, environmental exposures, and other aspects of a modern lifestyle can cause inefficient methylation. In addition, approximately 60 percent of U. S. adults have a genetic variation that makes it difficult for their methylation cycle to function optimally. Thornes Methyl Guard Plus features betaine (trimethylglycine), methylated vitamin B12