Mine and Mum's signs of low VitD levels were that we felt very tired. I would do 20 mins weeding then have to sit for 2 hours, without moving, simply hadn't the energy. GP prescribed capsules which really helped. I didn't have joint pain.
I do suffer with deep pain in the thighs. This is due to bending over cabinets at antique fairs, it wakes me in the night and is so painful that I can't even yelp. It took months to find out way but that is probably postural. Now that I am aware I take more time in between searching ........