Welcome Sylvia Rose! I think we must be two very odd ducks, but YES, I swear I feel worse when taking larger doses of VitD. My rheumy had Rx'd 50,000 units of Vit D (prescription dose) to be taken once a week for 8 weeks a couple years ago. After the first one, I had a muscle spasm in a new place, and worsening back pain. Things got even worse, pain and malaise wise after the second one, including more muscle spasms. I think I tried a third one and then called it quits - actually, so did the rheumy - telling me to go to 1000/day over the counter. Well, I felt so crummy, I didn't start the OTC right away - and the longer I stayed off the Vit D - the better I felt.
A year went by - Vit D checked again - and was told to get on 1000/day pronto and re-check the level in 2 mos. I followed orders. Went into big flare just after the two month mark. I went to a different lab for the re-ck and for some reason they did both the OH25 and 1,25. Rheumy's office called and told me to stop taking Vit D supplement altogether because the 1,25 level was extremely high. Also - the 0H25 was even lower than before I started the OTC.
Six months later, I see rheumy's PA who identifies osteoporosis and says I must bring up my vitamin D so I can begin taking Fosamax for the osteoporosis. Back to 50K weekly. (we all must be slow learners) I took two before going into another flare and stopping.
Fast forward to last summer. Was tested and diagnosed with Celiac disease. Vitamin D deficiency again noted. He wanted me to take 1000-2000 per day on top of Cal/Mag/Vit D supplement and the Vit D in a multiple vitamin. Same story - felt worse, stopped, started again at lower dose, several times. Now I'm taking about 500 per day in the Cal/Mag/D combo. I am still having major muscle issues - especially in my hips and knees - tops of thighs. I am sure it is the Vit D. Along with the muscle pain and weakness, throw in extreme constipation (I now eat prunes daily and a boost of magnesium every other day) and a return to a problem with heart palpitations which I have had over the years, but had not had problems with for quite some time.
I have asked the same question about Vit D on this forum, and most people seem to feel better on it. I am seeing Integrative Medicine doctor tomorrow. He won't be happy with my measley 500 mg. of Vit D - but I refuse to take more until he does the 1,25 test again and we see where that level is. If you google Vit D sensitivity or toxicity you will find some info. It would be important for you to know whether your calcium level is high - as excess Vit D can cause that - which can be a real problem. Mine has been on the high side of normal. I asked this doc if the Vit D could be causing the muscle problems, and he said yes, because I still wasn't absorbing due to the celiac, and it wasn't getting into my bones, but just circulating in my blood.....or somethingl that like.
Wow - sorry about the chapter book. If I get more specific info tomorrow, I'll post it. Labtestsonline.org explains the different tests. Good luck, and hope it helps to know you are not the only one !
Lucy