Holo-transcobalamin is an indicator of vitamin B-12 absorption in healthy adults with adequate vitamin B-12 status

Autor: David R. Maneval, Jonathan J. Shuster, Kristina M von Castel-Roberts, Ebba Nexø, Anne Louise Morkbak, Lynn B. Bailey, Claire A Edgemon, John F. Valentine, Gail P. A. Kauwell
Rok vydání: 2007
Předmět:
Zdroj: The American Journal of Clinical Nutrition. 85:1057-1061
ISSN: 0002-9165
DOI: 10.1093/ajcn/85.4.1057
Popis: Background: It has been hypothesized that the response of holo-transcobalamin (holo-TC) to oral vitamin B -12 may be used to assess absorption. To develop a reliable clinical absorption test that uses holo-TC, it is necessary to determine the optimal timeline for vitamin B-12 administration and postdose assessment. Objective: The objective of this study was to assess the magnitude and patterns of change in the postabsorption response of holo-TC to oral vitamin B-12. Design: Adult (18 -49 y) male and female participants (n = 21) with normal vitamin B-12 status were given three 9-μg doses of vitamin B-12 at 6-h intervals beginning early morning (baseline) on day 1. Blood was drawn at 17 timed intervals over the course of 3 d for the analysis of holo-TC and other indicators of vitamin B-12 status. Results: Mean holo-TC increased significantly (P < 0.001) from baseline at 6 h (11%) and 24 h (50%). TC saturation increased significantly (P < 0.001) from baseline at 12.5 h (33%) and 24 h (50%). The mean cobalamin concentration changed significantly (P
Databáze: OpenAIRE