Talk to Internal Medicine on Joints Pain

I have severe pain in my palms thumb side both hands that even i cant feel pressure or cant grip properly, what possibly could be the reason? And sometimes i have shooting pain in my legs that for some time i cant move what tests should be done or to Whch doc should i consult? I also had vitamin d deficiency before the result was 9 something for which doc gave me medicine that was 6 months before then again i got deficiency again another doc gave me different medicine, but what can be done for long term? Any multivitamins that should be taken after 30 as many of my friends take without doc prescription?