I exhibit many of the same symptoms you do--tired, achy, moody, perimenopausal. Although I have additional things as well. At age 49, with one 12-year-old son, it's no wonder I'm tired. The biggest thing is probably that I need more exercise. But, truth be told, the tiredness gets in the way.
My recent vitamin D2 level was 5; D3 was 20; D Total was 25 (should be greater than 40, according to my doctor).
My doctor prescribed 1000 i.u. a day and I also have a Verilux full-spectrum light (HappyLite Mini Ultra) which I try to use daily. (Prior to the winter, I got that light for around $50 on Amazon but I don't know what deals are out there right now.) I don't feel as moody these days, but I'm not sure if it's the vit D and light or some resolution of some challenges with my husband. Probably both.
There are so many things that could be interrelated. I'm on antidepressants which add to my weight which probably adds to the achiness and tiredness. And I had my right fallopian tube and ovary removed last summer, due to an abscess, and I'm sure my hormones are playing games with me. (When it rains, it pours! I think my whole body is quitting on me! : P)
I also was checked for my thyroid levels because my hair was falling out a couple of months ago. While I was in the hospital again in January 09, for another abscess on the OTHER side, my thyroid levels were low. But now that I'm out and recovered, it's fine again, which my doctor said is not surprising. Thyroid levels fluctuate when you are fighting infections, I guess.
It's important to know that you need some fat in your diet to absorb vitamin D. For those of us who drink skim milk, fortified with A & D, the D may not be getting into our systems. (Personally, I can't believe I don't have enough fat in my diet. I love Brummel and Brown too much on my toast! And cheeses, which provide fat along with protein : P)
I have been trying to establish better sleep hygiene (go to bed and wake up at more consistent hours). And trying to not get too much sleep. It turns out I was sleeping up to 10-12 hours a day which may have, ironically, been contributing to more sleepiness.
So, I guess I haven't given you any real answers. Just more examples. I suspect most of this is our hormones playing with us during perimenopause and, for me, a lack of exercise and being overweight. They all can contribute to the tiredness and achiness.
My doctor and I are still doing some additional tests to make sure. Keep us posted if you find anything else out. Sounds like a lot of us are tired, achy, and moody during this thing called perimenopause!