I Have Had Severe Back Pain For 5 Months. Had

I have had severe back pain for 5 months. Had 2 MRI's and they only show mild degenerative disc in L5 and S1 and doctors don't know why I'm in such debilitating pain. They put me on Neurontin and anti inflammatory. They took blood work testing for lyme disease and osteoarthritis. Do you think they also tested me for low vitamin D? I've been googling and it says low in vitamin D could cause back pain. Do you agree?