Abstract: A method of replenishing plasmalogens in mammals comprising treatment with a plasmalogen-replenishing-effective amount of one or more stantially pure monoethers of glycerols and their carboxylic acid ester derivatives of Formula I: wherein R is a C12-C22 linear or branched alkyl or alkenyl group; and R1 and R2 are, each independently, hydrogen or an acyl moiety {—C(═O)—R3} wherein R3 is a linear or branched C1-C30 alkyl or alkenyl; and pharmaceutically-acceptable salts thereof, is disclosed. Nutritional supplements, dietary supplements and food additives comprising one or more substantially pure compounds of Formula I is also disclosed.