Real causes of fatigue in thalassemia (minor)

I have read lots of good information here .Thanks to Everyone that have been posting .
I'm in Bed resting right now. I have been feeling lack of oxygenation too. I finally came to realized that this us the cause of the fatigue. But all the explanation about inflammation and allergies is very interesting. I had an allergy test done last September and I'm virtually allergic to everything ( at least at this point )I'm an alpha thal minor but last couple years thallassemia has giving me a challenging time. The way I have been feeling lately  I'm sure my MD doctor would send me to the hematologist to have some iron infusions done. I realy hope my naturopathic doctor can help me with the oxygenation .
I'm taking some supplements for the allergies, for the missing gallbladder and
Vitamin B,D, Coq10
Last bloodwork was fine but I still fatigued

During 2007-2010 I was diagnosed of following in USA hard wintry months:
- hypothyroidism
- B12 deficiency
- Later in 2010 I was diagnosed with Vitamin D deficiency (it appeared 5 in the blood tests)
(my joints always pained severely in the wintry snowy months)

Doctors started medicines like below:
- levothyroxine 50 mcg, 75 then 88 and then 100 mcg
- B12 shots (cyanacobalamin) -- starting weekly, then monthly(11) then one every quarter
- 2000 IU of VitaminD3 soft gels twice a day to be taken exactly 12 hrs apart (eg 8am and 8pm)
I purchased OTC Carlson 2000 IU soft gels from Amazon.com

Within 6 months, my Vitamin D levels shot to 60. I thought the same would remain in my body for long.
I quickly forgot to take D3 supplements after returning to India.
Thus, in Aug 2013 my Vitamin D fell to 14.44
I was asked to take some D3 shots however fearing the painful oily shots, I continued on oral supplements of D3

I usually take D3 tablets twice a day from October or November and continue the same until Feb or March in India.
I also take them one month in July and August when it rains heavily in India and bones can pain.

I prefer and do take B12 shots but never the D3 shots. They are oil based formula and are quite painful at the time they are given followed by sustained pain for 24 to 48 hrs. I avoid D3 shots.

My own analysis for fighting fatigue in beta thal patients is:
- take regular folic acid tablet but do try to give a gap sometimes (you dont want flood the system with RBCs)
  eg take folic acid 5 mg tablet every day for 45 days and then give a gap for 10-12 days, again start
- take regular B12 shots (one per quarter methylcobalamin 1000 mcg)
- take B6 Pyridoxine Hcl tablets only for a week when you are going to take B12 shot
- Vitamin D3 soft gels to be consumed just before wintry months and stop when sunny months appear

Thanks,

My doctor has me taking vitamin D even in the summer. It really depends on how much sun exposure you get. Do you wear long pants and long sleeves in the summer? If so, you may still need D during those months.

Yes, in India I still wear long pants and long sleeves shirts all 52 weeks.

This morning I took weekly dose of my Vitamin D3 1gm granules (60,000 IU) dissolved into a cup of milk and consumed it. Last 3 days have been scorching hot sun on continental India with some sudden heat increase.
Tomorrow morning is my B12 500 mcg weekly dosage due.