I wanted to address the issue of Vitamin D2 and Vitamin D3 right away. My goal here is to give you more information that you can discuss with your doctor - to help you make the best choice. This isn't rocket science - I just did some online research - and I have also been able to talk to Dr. Cannell several times in the past. There is a website called Better Bones - and there is a quote from Dr. John Cannell - one of the world's leading experts on Vitamin D - that is posted there. If you type "What is the difference between Vitamin D2 and Vitamin D3" into your browser, it will come up. Here is what Dr. Cannell said (ergocalciferol is Vitamin D2 and cholecalciferol is Vitamin D3):

Which Form Should I Take, Vitamin D2 vs D3?
“If you take ergocalciferol, or “vegetarian” vitamin D, be warned. Ergocalciferol is not vitamin D, but a vitamin D-like patent drug whose patent has expired. It does not normally occur in the human body and is probably a weak agonist at the receptor site, meaning it may actually partially block vitamin D actions. Ergocalciferol is the villain in most of the reported cases of toxicity in the world’s literature. All bets are off in terms of measuring blood levels if you take ergocalciferol. Some of the labs can pick it up, and some can’t. Don’t take ergocalciferol; it is not vitamin D.” For more details, see Dr. Alan Gaby’s summary of the research comparing vitamin D2 and D3.

Here is the reference for Dr. Gaby's work: Gaby AR. Vitamin D3 more potent than vitamin D2. Townsend Letter for Doctors and Patients, October 2005.

Dr. Mercola has also been very enthusiastic about Vitamin D3. You can find both doctors on You Tube talking about Vitamin D3. There are MANY doctors on YouTube talking about Vitamin D. Even Katie Couric is on YouTube discussing Vitamin D3. Many of the talks on YouTube are discussing the outdated notion that 400 IU of Vitamin D3 is sufficient. That has since been debunked.

https://www.youtube.com/watch?v=--NqqB2nhBE. Dr. Cannell has spent decades researching Vitamin D. I'm really glad I found this talk by him so I don't have to write anything further.

This will give you more information to discuss with your doctor. As always, ask your doctor what s/he thinks. I MUST avoid Vitamin D2 because I have candida overgrowth and D2 has a yeast background.