You can use this database or one you like. You can count total choline but I dont know if free choline is as good as phospatydylchloline. For calculating take last few days and average it out, if dont eat the same things all the time.
http://www.ars.usda.gov/SP2UserFiles/Pl ... holn02.pdf
http://www.ars.usda.gov/SP2UserFiles/Pl ... holn02.pdf