Donor post transplant B12 deficiency

[Daka]

I donated a kidney three months ago. I have been taking self-injections of B12 (hydroxococobalamin) for 25 years. Post transplant three months my B12 dropped significantly and I am now taking the injections every second day for two weeks to boost the B12. Has anyone else experienced a B12 deficiency post transplant? My transplant team tells me it is not related to the transplant but I am not convinced.