Regardless of how your blood tests turn out, you should try to follow a gluten-free diet afterward. There's a great thread here on the Forum entitled either Celiac 101 or Gluten-free 101 (sorry--I can't recall). Someone will jump in shortly, I'm sure, to help you find the correct thread. Generally, though, when you begin a gluten-free diet, it's best to stick with natural foods (meats, dairy, vegetables, fruits, nuts, rice, etc.). This way, your chance of cross-contamination goes way down. Also, if you attempt to eat the gluten-free versions of your favorite foods right away, you may react to the special grains and/or gums that are used and may think that the gluten-free diet isn't helping you. After a few months of eating just natural foods, you can begin to explore gluten-free alternatives....and there are some very good ones out there. Just read some of the postings on this Forum--you'll get lots of great advice!
Also, you should begin addressing your other nutritional deficiencies as soon as possible. For your Vitamin D deficiency, you'll need to take Country Life Natural Vitamin D. The reason for this is that you also need to take Vitamin A at the same time (your cells have two A receptors for every D receptor), and it also contains medium-chain triglycerides to help you absorb both Vitamins D and A. I actually was taking 50,000 iu's of Vitamin D daily for a year--and I couldn't overcome my Vitamin D deficiency. However, when I attended a celiac conference last June in Seattle, one of the presenters discussed how taking Country Life Natural Vitamin D can help celiacs overcome their Vitamin D deficiency--and after only a few months, my Vitamin D level was extremely healthy (and I only take 400 iu's a day!).
You're heading in the right direction....now go and get healthy!