title: Choline intakes exceeding recommendations during human lactation improve breast milk choline content by increasing PEMT pathway metabolites.
abstract: Demand for the vital nutrient choline is high during lactation; however, few studies have examined choline metabolism and requirements in this reproductive state. The present study sought to discern the effects of lactation and varied choline intake on maternal biomarkers of choline metabolism and breast milk choline content. Lactating (n=28) and control (n=21) women were randomized to 480 or 930 mg choline/day for 10-12 weeks as part of a controlled feeding study. During the last 4-6 weeks, 20% of the total choline intake was provided as an isotopically labeled choline tracer (methyl-d9-choline). Blood, urine and breast milk samples were collected for choline metabolite quantification, enrichment measurements, and gene expression analysis of choline metabolic genes. Lactating (vs. control) women exhibited higher (P < .001) plasma choline concentrations but lower (P ≤ .002) urinary excretion of choline metabolites, decreased use of choline as a methyl donor (e.g., lower enrichment of d6-dimethylglycine, P ≤ .08) and lower (P ≤ .02) leukocyte expression of most choline-metabolizing genes. A higher choline intake during lactation differentially influenced breast milk d9- vs. d3-choline metabolite enrichment. Increases (P ≤ .03) were detected among the d3-metabolites, which are generated endogenously via the hepatic phosphatidylethanolamine N-methyltransferase (PEMT), but not among the d9-metabolites generated from intact exogenous choline. These data suggest that lactation induces metabolic adaptations that increase the supply of intact choline to the mammary epithelium, and that extra maternal choline enhances breast milk choline content by increasing supply of PEMT-derived choline metabolites. This trial was registered at clinicaltrials.gov as NCT01127022.
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Crystal
authors.initials: C
authors.lastname: Davenport
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Yan
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Siraphat
authors.initials: S
authors.lastname: Taesuwan
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Shields
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Allyson A
authors.initials: AA
authors.lastname: West
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Xinyin
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Cydne A
authors.initials: CA
authors.lastname: Perry
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Malysheva
authors.affiliation: Department of Medicine and Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA.
authors.forename: Sally P
authors.initials: SP
authors.lastname: Stabler
authors.affiliation: Department of Medicine and Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Allen
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA. Electronic address: mac379@cornell.edu.
authors.forename: Marie A
authors.initials: MA
authors.lastname: Caudill
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002794:Choline / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood / Q000378:metabolism; D015331:Cohort Studies; D003903:Deuterium; D019587:Dietary Supplements; D004790:Enzyme Induction; D005260:Female; D006801:Humans; D007774:Lactation / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007962:Leukocytes / Q000201:enzymology / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D042361:Mammary Glands, Human / Q000201:enzymology / Q000378:metabolism; D039382:Maternal Nutritional Physiological Phenomena; D008895:Milk, Human / Q000737:chemistry* / Q000378:metabolism; D009518:New York; D050918:Phosphatidylethanolamine N-Methyltransferase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D064167:Recommended Dietary Allowances; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D003903:Deuterium; C494489:PEMT protein, human; D050918:Phosphatidylethanolamine N-Methyltransferase; D002794:Choline
keywords: Choline; Human milk; Isotopic labeling; Lactation; PEMT