Mrs. D just responded to a similar question a few posts down (at the moment).

You probably want to take D3 as this has been shown to work better in the body than others.

I personally think being low in Vitamin D might cause muscle aches.

Overall, Vit. D helps the body in many, many ways...so you will want to correct this ASAP.

What dosage does the doctor want you to take? If he prescribed D2 (ask the pharmacist if you are not sure), you might want to talk with a different doctor for a second opinion. If you are on your own with this, talk with a really good pharmacist about getting on a good brand of D3 and what dosage you should take. My guess is it should be at least 4000 units daily (only a guess). Please follow up on this. It might very well make you feel better and there are lots of studies that indicate D3 is very necessary for our overall health.

By the way, if you can tolerate it, a short walk in the morning to get a little sun might also be of help (plus getting the D3 tablets/gel tablets are said to be best)

Again, get some D3 and more info....nice chance you will feel better.