Increases in plasma holotranscobalamin can be used to assess vitamin B-12 absorption in individuals with low plasma vitamin B-12.
Bhat DS, Thuse NV, Lubree HG, Joglekar CV, Naik SS, Ramdas LV, Johnston C, Refsum H, Fall CH, Yajnik CS. J Nutr. 2009 Nov; 139(11):2119-23. Epub 2009 Sep 23.