We've discussed this here before, but I thought I would put up a link to some current thinking from a very unbiased source, Scientist magazine.

http://the-scientist.com/2012/03/01/vitamin-d-on-trial/

nI actually almost participated in a clinical trial prior to my surgery - I would have had to take high doses of Vitamin D. The study was to determine the what high doses of Vitamin D do to cellular structure, among other things.

I am a big believer in the power of vitamins and nutrients in healing. Currently I have upped my intake of vitamins, and nutrients, especially those with a demonstrated effect on cancer and oral health (such as those containing vitamins A, B, C, D and K).

The way I see it, definitely cannot hurt...

Make sure that you discuss EVERY supplement that you take with your doctors. Somethings that you may believe to be beneficial, will actually interfere with the treatments.

Very Interesting article. Thank you Brian
Both my cardiologist and my endocrinologist are emphatic that I need to take 4000 IU of Vitamin D daily after they reviewed my first blood tests after cancer TX that my radiologist had recommended. It's great that there is a routine blood test that can accurately determine whether or not your diet or pills is giving you enough Vitamin D.
Many of us radiation survivors are extremely sensitive to sun damage on our skins so we can't rely on sunshine and being outdoors as that study mentioned since a really effective sunscreen also blocks the Vitamin D absorbtion effect.
None of my doctors saw any downsides nor had seen adverse effects of Vitamin D supplementation in their patients.
Charm

Since Kris's recent total glossectomy/laryngectomy he has to take Vitamin D in the form of Calcitriol 2mcg per day
Post surgery he had severe calcium deficicency leading to tetany spasms and required 5 days of IV calcium replacement.
His Parathyroid gland is no longer functioning, so no hormone to stimulate release of calcium from bones. He has been on both calcitriol and calcium supplements. However at this weeks appointment with endocrinology the calcium has been stopped. He should be getting adequate calcium from the Fortisip, but will always have to take the calcitriol.
Interestingly, his Thyroid gland has also stopped functioning so is also now taking thyroid supplements. This was also discovered during his recent surgical admission.
The Drs attributed the thyroid dysfunction to the previous radiotherapy - completed 12 months prior. But not the Parathyroid. This they have put down to damage during Kris's extensive bilateral neck dissection performed during the recent surgery.
Life keeps getting more complicated. But we manage.
Tammy

I'm going to mimic Brian, I believe in the power of diet in reference to health, and healing and fighting disease, that said, during treatment I stopped ALL supplements including regular vitamins, certain things are counterproductive to radiation, and I waited 4 mos to start taking vitamins again. Right now I take circumen, vitamin d, green tea, and a daily vitamin.