Betaine

About Betaine

Betaine, also called trimethylglycine or TMG, is a derivative of glycine carrying three methyl groups on its nitrogen atom, giving it the form of a zwitterion. It was first identified in the nineteenth century in sugar beet, and its name comes from Beta vulgaris, the botanical name of the beet. Food sources include beets, spinach, quinoa, and wheat bran, and the body also makes betaine by oxidizing choline. Betaine acts as an osmolyte, protecting kidney and other cells from osmotic stress, and as a methyl donor for betaine homocysteine methyltransferase, which converts homocysteine back to methionine in the liver and kidneys, independently of the folate and vitamin B12 dependent pathway. Betaine anhydrous is an FDA approved drug for homocystinuria, a rare inherited disorder causing very high homocysteine levels. It has also been studied for fatty liver disease and exercise performance, with mixed results. Gut bacteria can convert betaine to trimethylamine, a precursor of TMAO, whose clinical significance is debated.