I discovered my Alpha-Thal Minor trait several years ago after questioning my doctor about the irregularities in my CBC. Specifically, I wanted to know why the MCV and MCH were both so low. During this period, I also had chronic bone pain in my legs, pale skin and fatigue, however my doctor said that A-Thal-minor did not cause symptoms, hence I moved on with my life in spite of my symptoms.  
I'm so happy that I discovered this forum and the recommendation of taking folic acid. Soon after starting the supplement ( 1.6mg), my symptoms began to get better.  Therefore, my question is exactly how much ( mg) of folic acid should I supplement with per day? 
By the way, listed below are recent labs. 
F   WBC   3.0  L   4.0-10.5 (K/uL)
F   LYMPH#   1.1   0.6-4.1 (K/uL)
F   LY%   37.1   10.0-58.0 (%)
F   MID#   0.3   0.0-1.8 (K/uL)
F   MID%   9.9   0.1-24.0 (%)
F   GRAN#   1.6  L   2.0-7.8 (K/uL)
F   GRAN%   53.0   37.0-92.0 (%)
F   RBC   5.89  H   4.10-5.60 (M/uL)
F   HGB   14.8   12.5-17.0 (g/dL)
F   HCT   47.4   36.0-50.0 (%)
F   MCV   80.5   80.0-98.0 (fl)
F   MCH   25.1  L   27.0-34.0 (pg)
F   MCHC   31.2  L   32.0-36.0 (g/dL)
F   RDW   13.1   11.7-15.0 (%)
F   PLT   239   140-415 (K/uL)
F   MPV   9.7   0.0-10.0 (fl)
F   Vitamin D-25   30.2   30.0-100.0 (ng/mL)