Methionine

Another enzyme belongs to Lipotropic Compounds is Methionine, which is one of the sulfur containing amino acids and is important for many bodily functions.  It acts as a lipotropic agent to prevent excess fat buildup in the liver and the body, is helpful in relieving or preventing fatigue and may be useful in some cases of allergy because it reduces histamine release. 
Methionine synthase (MTR) is a methyltransferase enzyme, which uses the MeB12 and reaction type 2 to catalyze the conversion of the amino acid (Hcy) back into methionine (Met).  This functionality is lost in vitamin B12 deficiency, and can be measured clinically as an increased homocysteine level in vitro. Increased homocysteine can also be caused by a folic acid deficiency, since B12 helps to regenerate the tetrahydrofolate (THF) active form of folic acid. Methionine combined with choline highly helpful to break down fats in the body and prevents fat build ups in the liver which helps to weight loss and control the body weight.