Study schedule
STERILE, BLOOD
Directly prior to use, substances were dissolved/emulsified in 10 ml sterile water and topped up with 250 ml apple spritzer. Test subjects had to ingest in a randomised sequence at least 6 weeks (w) apart D9-choline metabolite for wash out.D9-choline chloride (3.6 mg/kg),D9-phosphorylcholine chloride (6.4 mg/kg),D9-alpha GPC (6.4 mg/kg) orD9-POPC (18.6 mg/kg)Experiments started in the morning after overnight fasting, and the supplement was served in 250 mL apple spritzer together with a butter pretzel (102 g) containing 16.9 mg total choline and 10.3 mg betaine as well as 12 g fat. Detailed composition of the study meal fatty acids is shown in Table s1 of the online supplement.Blood (2.7 ml EDTA) was taken before intake (− 0.1 h) and at 0.5 h, 1 h, 1.5 h, 2 h, 3 h, 4 h, 5 h, 6 h, 9 h, 24 h, 33 h and 48 h, 3d, 4d and 7d after D9-choline intake. Test persons fasted until the 6 h-blood sample was collected. Collected blood was immediately centrifuged at 1000x