How many of the people with anemia are treatable, and how many are just born that way and untreatable? 50%/50%?

Majority treatable: There are a lot of causes of anemia- the most common are perhaps blood loss, decrease production- due to iron deficiency, vitamin deficiency, anemia of chronic disease - these are treatable minority cases such as hereditary anemia- such as diamond blackfan syndrome, fanconi's anemia, cooley anemia-much harder to treat-supportive tx only and bone marrow transplant to treat if possible.