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)
This is why you might take supplements for months and still not feel a difference
One week you feel fine, the next you are dragging through mornings, losing focus by mid-afternoon, and relying on caffeine just to keep up
Why might you need Lipo B12
Mic B12 Injections Cost: Price Ranges & Will Insurance Pay For Your Shots