<s>[INST] context: Vitamins are organic molecules that function in a wide variety of capacities within the body. The most prominent function of the vitamins is to serve as cofactors (co-enzymes) for enzymatic reactions. The distinguishing feature of the vitamins is that they generally cannot be synthesized by mammalian cells and, therefore, must be supplied in the diet. The vitamins are of two distinct types, water soluble and fat soluble Alpha-lipoic acid, LA, (chemical name: 1,2-dithiolane-3-pentanoic acid; also known as thioctic acid), is a naturally occurring dithiol compound synthesized enzymatically in the mitochondrion from the medium-chain fatty acid octanoic acid. Because LA can be synthesized in the body it is not technically considered a vitamin but because of its vital role in overall cellular metabolism, it is considered as an impoant, but not necessary, dietary supplement. Given that LA is a necessary cofactor for mitochondrial a-ketoacid dehydrogenases, it thus serves a critical role in mitochondrial energy metabolism. In addition to de novo synthesis, LA is also absorbed intact from dietary sources, and it transiently accumulates in many tissues [/INST] question: Non-vitamin coenzyme is | options: A: Lipoic acid B: CoA C: S-adenosyl methionine D: Niacin | answer: A </s>