Letter: The aging gastrointestinal tract.
D000284:Administration, Oral; D000375:Aging; D004064:Digestive System / Q000378:metabolism*; D006801:Humans; D007408:Intestinal Absorption; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism; D014815:Vitamins / Q000008:administration & dosage / Q000378:metabolism
D004364:Pharmaceutical Preparations; D014815:Vitamins