The above is usually talked of in terms of 'anaemia', but it does show that there is a complicated link between B12, B6, folic acid, zinc and vitamin D levels, chronic disease (anaemia of chronic disease) and how the body 'manages' serum iron, ferritin, and transferrin iron saturation and keeps these in balance (or not, as in your case)
A key study published in the Journal of Clinical Endocrinology and Metabolism enrolled 118 GH-deficient adults and demonstrated a 30-40% increase in serum IGF-1 over 6 months of nightly subcutaneous dosing
The cycle runs 4 weeks on, 2 to 4 weeks off
It's not always the case, but I would have expected something as well as an unmeasurable B12
The right plan depends on several factors that should be reviewed by a qualified provider before use