I also found this from Rich about carnitine and methylation.
I just want to note that several studies have shown that carnitine is low in ME/CFS. I think the reason is that methylation is required to make carnitine in the body. One of the main roles of carnitine is to usher fatty acids into the mitochondria of cells to be burned as fuel. In the urine organic acids test results that many people have posted or sent to me, I usually find that the fatty acids markers are showing buildup of omega oxidation of fatty acids, which occurs when there is a carnitine deficiency. Under these conditions, it makes sense that your muscles would respond to carnitine supplementation, since it raises the supply of fuel to their mitochondria. When the methylation cycle partial block has been lifted, the cells should be able to make enough carnitine for themselves.
SAMe is produced in the methylation cycle and is the main supplier of methyl (CH3) groups for a large number of methylation reactions in the body, including the methylation of DNA and the biosynthesis of creatine, carnitine, phosphatidylcholine, coenzyme Q10, melatonin and epinephrine. This measurement is made in the red blood cells because the level there reflects an average over a longer time and is less vulnerable to fluctuations than is the plasma level of SAMe.
Best regards,
Rich