I think you should see a lot of improvement. From what I understand, you need D3 to process other vitamins such as C, so if you have low D3 and are tested for say, Vit C deficiency, your C blood levels will be normal, but your body is unable to utilize the C because your D3 levels are so low.
I was taking one 50k iu pill every Friday for 4 months (via prescription), then I bought the 10k iu's and was taking 5 of those a week (over 5 days) for the balance of the year. Now that I know my level is 45 and I feel better, I am taking 30k iu per week. Docs will tell you to be careful w/ D3 because it is fat soluable, which means it can build up in your system.
Other things I have done over the past few months or so to feel better are (I did/am doing one at a time to see if there is a benefit or not):
Remove all soy from my diet. I am not allergic, but soy has an estrogenic effect on the body. Soy is an additive in MOST processed foods.
Remove all artificial sweetners from my diet. I started off by removing caffiene but didn't feel any better months later so went back on caffiene but removed the
Aspartame from my diet (Diet Coke, yogurt, etc...) and that helped with a lot of issues.
More recently, I removed all parabens from my life (lotions, hair products, make up, etc...) and replaced them with homemade alternatives.
Removed all corn syrup from my diet (mostly I consumed high fructose corn syrup).
Now I am working on removing all chemical cleaners (laundry soap, window spray, etc...), pesticides (used in my yard) and a slow switch to organic foods. Oh, also removing all silicones (silicone in my shampoo - searching for alternatives).
I have also started turning off my wifi from 9 pm to 5 am (sleeping hours) after years of having sleep problems, this is working extremely well. I find that
Cell Phone + wifi internet make me feel extremely fatigued and increase anxiety. I also periodically turn off my
Cell Phone during the day. I am going to find a good alarm clock so I can sleep w/ my
Cell Phone off (I use it for my alarm right now).
A long term goal that will happen very slowly due to the expense of it is to remove all PVC/plastic wallpaper and food storage from my house. As for right now, I pick up glass containers at thrift stores and drink out of a glass glass, eat off glass, use stainless steel utensils whenever possible.
I still smoke cigarettes by the way, I have made several serious attempts to quit over the past year but have not yet succeeded. It is the final frontier.