Effect of vitamin B12-deficiency on % 5 mdC1 for DNA extracted from coagulated blood clots2 and uncoagulated EDTA-blood cell pellets3.

1Methyldeoxycytidine as a percentage of total deoxycytidine in DNA digests, measured by LC-MS/MS (see Methods).2Post-centrifugation, blood clots were retained after serum was removed from serum blood tubes.3Post-centrifugation, blood cell pellets were retained after plasma was removed from EDTA-blood tubes.4Results for all assayed blood clot DNA.5Matched data for blood clot and EDTA-blood cell pellet DNA from the same subjects.6Subjects with plasma vitamin B12 more than 148 pmol/L.7Subjects with plasma vitamin B12 less than 148 pmol/L.*Power analysis: >80% confidence to detect a 2% difference in means [62].