People talk about low ferritin but I know you have to be careful about overdosing on iron. I am 61 yrs . My hair has been falling out since I have been on levo. Pumping myself up with b 12 and d3 vit and b complex as well . My ferritin on my last blood test reads 33 range(15-150) I have been on Levon for about 8 months.