Formulation of Vitamin A Tracer Doses for Administration to Human Subjects using Retinol Isotope Dilution Technique

C] with >95% all-trans isomeric purity and >99% isotopic enrichment. The preparation of the vitamin A stable isotope tracers involves dissolving the tracer in edible vegetable oil through sonication and heat. Tracers need to be prepared at a concentration that is well within the volumetric limits of the delivery system. Finally, the tracer is aliquoted into sterile amber glass vials, and tracer concentrations are confirmed spectrophotometrically.