EDTA plasma rather than serum for B12, folate and ferritin estimations?
D005293:Ferritins / Q000097:blood*; D005492:Folic Acid / Q000097:blood*; D006801:Humans; D010949:Plasma; D014805:Vitamin B 12 / Q000097:blood*
D005293:Ferritins; D005492:Folic Acid; D014805:Vitamin B 12