“…In a survey of 473 free-living or institutionalized elderly, essentially all were found to have normal blood biotin levels (11). Urinary biotin excretion is lower in subjects with achlorhydria, possibly because release of food-bound biotin is impaired (106). Urinary biotin excretion is lower in subjects with achlorhydria, possibly because release of food-bound biotin is impaired (106).…”