Dr. John Cannell has spent significant time in reviewing research from the 30’s in using extreme amounts of vitamin D to treat disease. This is well worth the read.
I am amazed at the amounts of vitamin D and the fact that all did not die. In particular since they were using D2 and ran the risk of over irradiation and forming toxisterols.
Check it Out: Gary Null and Vitamin D Toxicity
Vitamin D in large amounts can be toxic. If you want to try more than a million IU for an infection or other disease then you should see your doctor. It is not the amount that you take, it is keeping your serum level consistently under 200 ng/ml. See last line table one NIH Fact Sheet Of course that argument fails when you start to take in the millions of IU’s.
For best results in treating chronic disease then keep your 25(OH)D3 level to that of a sunny country 54 to 90 ng/ml. (Grant and Holick) Please notice that I said D3 in the 25(OH)D3.
Typical amounts of vitamin D3 from all sources should be around 40 IU of D3 per pound of body weight per day. This should keep you under 10,000 IU per day unless you are reallly large.
Vitamin D Deficiency Survivor 
I am another vitamin D3 insufficiency survivor (but just barely). No one warned me that getting into my 80’s and not getting out-of-doors much had really serious vitamin D3 consequences. Like developing adult scoliosis *I can’t see the top shelves at the supermarket anymore), crumbling teeth (they just broke off for no reason), and a diagnosis of blood pressure out of control. The blood pressure bit is interesting, since the problem is that vitamin D regulates the parathyroid, and without enough D the parathyroid hormone level increases, and that in turn drives up blood pressure. When I leaned of this I took increasing amounts of D3 until my blood pressure came down and got under control. That meant 15,000 IUs per day, which is well above that recommended by D3 knowledgeable MDs. I have tried to drop down to 10,000 IUs four different times and was smacked back up each time. One time with an immediate allergic reaction (face swelling) and the other three times my blood pressure began to increase. My D3 level is 92 ng/L and my doctor says it is the highest he has ever seen and wants me to cut my daily dosage in half. That accounted for my fourth unsuccessful attempt to cut back. I imagine that the reason my doctor hasn’t seen a vitamin D level as high as mine is that we both live on Bainbridge Island, WA. At this latitude the sun may shine, but it doesn’t matter all that much as far as vitamin D production from sunlight exposure is concerned.
Father William,
This is a difficult problem both for people suffering from disease and for doctors trying to operate within medical guidelines. What it really comes down to is a matter of education. The NIH fact clearly says that a 25(OH)D level consistently below 200 ng/ml is safe. See the link in the above article and see table 1. Your doctor may not be aware of the NIH’s position on the safety of vitamin D based on the statements in this fact sheet.
I would point this out to your doctor and ask him, with his knowledge of the side effects of high blood pressure drugs, which is safer. A serum level of 92 ng/ml is the top end of what you find in a sunny country (Grant and Holick) and should be safe. I agree with your assessment of your doctor’s experience because of latitude.
Your story is a clear indication of the need for doctor education. The total benefits of vitamin D is more important than the lack of education of your doctor.