The Nutrition Research Institute conducts quantitative targeted analysis of biospecimens (e.g., plasma, serum, urine, stool, breast milk, and seminal plasma) to determine levels of choline and choline-related metabolites (e.g., methionine, trimethyl amino oxide, betaine, phosphorylcholine, phosphatidylcholine, glycerophosphocholine, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine, creatinine) that are associated with disease, dysfunction, or dietary intake.