I have been reading lots of articles in the last few years about how many, of not most, of the people in the western world are deficient in Vitamin D. The standard "wisdom" has been for decades that 15-20 minutes of sunlight daily will be sufficient to allow our bodies to make enough Vitamin D. But then they say "oh, yeah, well people with darker skin need more time in the sun." And they leave out the part where the Weather Frog (that's the German version of the Weather Man) predicts that you won't see the sun for another couple of months because it's winter time here in the frozen north. And they leave out the part about most of us spending our days indoors at desk jobs instead of being outside tending our farms. And they leave out the part where even people who do live in sunny environments and who do get frequent time in the sun also have low Vitamin D levels.
What I am waiting for is articles discussing the reasons
for this Vitamin D deficiency in so many people.
In the meantime, I am taking 2000 IU Vitamin D3 every day all year long, because I live in the dismal grey cloudy depressing north of Germany, and I would rather sit in front of my computer than expose myself to fresh air.
And besides, did I mention that the sun don't shine here? I started taking Vitamin D a couple of years ago when my depression got so bad that I was contemplating suicide. Since I have been taking it, I'm actually happy most of the time instead of the gloomy grump that I was for most of my life.
All of this blathering is to say that I am not surprised that your Vitamin D level is low. I am sorry that your symptoms caused you so much pain and that so many doctors didn't even think to notice it. Vitamin D is such an important nutrient that affects so many functions in our body. The articles that I have been reading over the years keep adding more and more bodily functions that are affected. This is how I figured out that my depression was caused by a deficiency.
I am glad that you have a doctor who is willing to run a blood panel for you, and to actually pay attention to the numbers that show up. I hope that your Vitamin D therapy will raise your levels sufficiently to make a real difference in your pain levels. Do keep taking the dosages as advised by your doctor. And keep us posted about how things turn out.