And - late to the party again I'm afraid - but (to cover answers to both of you):
I was 52 when PMR first started but relatively mildly and had it for 5 years with no treatment before it went mad
I have NEVER had a raised ESR or CRP level
I have never been anaemic (I now live at an altitude of 850m which may have an effect and spent a lot of time here in the winter then - but I doubt it)
One in six patients with PMR have blood levels within the normal ranges quoted by the labs.
Normal blood values and unusual symptoms are more common in younger patients.
I have never lost weight with PMR, in fact in the first 5 years I put on weight steadily because of being unable to exercise properly
That is an extremely low vit D level and even if it isn't the cause of the muscle pain it won't be helping
That dose of vit D will take until kingdom come to raise your vit D level (have you done the recommended reading about vit D?). You need high dose injections.
Your vit D level is affected by several things: there is almost none in our diet in Europe, getting older impairs the process of making it in the skin, most people north of Turin in Italy don't get enough sun anyway, using sunscreens (even factor 8 ) reduces the production to about 5% of the maximum you can manage.
What you describe is a fairly dramatic response to pred! They look for a 70% response in symptoms within a couple of weeks to a trial dose of 15mg/day by mouth.
Steroid injections have not been shown to be an adequate way of treating PMR. The effect wears off after a few weeks at most and often PMR is diagnosed after an injection in a shoulder or hip because of suspected bursitis - which is also a part of PMR - and finding that other symptoms improve too. But even several injections won't achieve a lot according to the medical literature.
So on balance - I can't say I am particularly impressed by the knowledge on the part of GP or rheumy as described here. Download the Guidelines on diagnosis and treatment you will find on the recommended sites and hand them over to the doctors for their perusal and edification.
Oh yes - someone mentioned an "urgent referral". That merely means you might be seen sooner than the current 18 week limit on waiting times (unless, of course, that is another target removed by the current gubmint). It does NOT necessarily mean you will be seen soon.
And although this isn't meant to be scary: if you have PMR you are at a higher risk of developing GCA, another closely related vasculitis, and that can affect your eyes and cause blindness. About 1 in 6 patients with PMR develop GCA at some time, the rate is higher for patients not treated with steroids. If you get any funny visual symptoms, pain in your jaw when chewing or a really bad new headache - go to A&E and tell them everything. Once your sight is gone it is too late to treat it.
Hope I didn't forget anything
Eileen