Pre-vetting a discussion for my oncologist's consideration

Many doctors are not knowledgeable about supplements. They may be terrific experts in their specialty, but with no training in nutrition. I am seen at MSKCC and the doctors didn't discuss supplements. Fortunately they have a top notch hepatobiliary dietician who was able to give information about many things. I haven't been able to get an answer on the vitamin D. I was hoping to have a diagnosis that would definitely cover the vitamin D test with my Medicare coverage. The diagnosis of vitamin D deficiency ;didn't assure coverage. Levels of vitamins can be checked and this seems like a useful way to go. Might not be covered but at least there would be an objective measurement that can be followed. Oncology certified dietician might be able to give more information than the physician since nutrition education is not part of standard medical training.

to ajh5285 below are some links to articles I've read about curcumin. I too have difficulty getting answers from oncologists about off label drugs and supplements. My husband has Stage IV and is getting chemo, and we have discussed baby aspirin, metformin and tumeric(circumin) w the drs. He takes Vit D and Zinc and they don't have a problem w that. He is treated at Dana, but we also went to Sloan this week. They have more of an integrative medicine dept there, and we are going to do a telemed call with that dept. See the link below. Sloan has a detailed website that describes all the supplements. The dr at Sloan didn't have an issue with him taking Vit D either. The site does not list the contraindications for curcumin to include the chemo--they list only possibility of kidney stones. All the drs want "evidence based clinical trials" for these off label drugs, even if there are numerous articles or smaller trials that have been done. BUt did you know that if a drug company sponsors a trial that they very often withhold the clinical trial results from the drs? The drug companies control the information and the marketing, so I'm not sure how good that "evidence" is, if the trials are not peer reviewed. And big pharma will not pay for clinical trials for an off label drug where the patent is gone, because they can't make money. There is a clinical trial at MD ANderson for hydroxycholoroquine, and I have inquired about that. It's very difficult to get consistent answers on the vitamins/supplements/off label drugs. Here are links:
Curcumin Combination Chemotherapy: The Implication and Efficacy in Cancer - PubMed (nih.gov)
Turmeric | Memorial Sloan Kettering Cancer Center (mskcc.org)
Curcumin-cisplatin chemotherapy: A novel strategy in promoting chemotherapy efficacy and reducing side effects - PubMed (nih.gov)
Curcumin and its derivatives in cancer therapy: Potentiating antitumor activity of cisplatin and reducing side effects - PubMed (nih.gov)

Thank you. I should probably have clarified that I have had my vitamin D levels measured a couple of times, one was done before my current health catastrophe had declared itself (diagnosed now with inoperable adenocarcinoma of the pancreas) and once since. Both test results were WNL (within normal limits) but not by much.
On Sep 15, 2022 my Vitamin D, 1, 25-Dihydroxy was measured as 21.3 [19.9 - 79.3 pg/mL = normal range on a test that came with the comment that it was primarily indicated for pt eval for hypercalcemia & renal failure, and was not the recommended test for deficiency (that is Vitamin D 25-hydroxy.
For the second test drawn on February 24, 2023, my level was measured as 32 [30 - 80 ng/mL]; this was a different test designed for those not taking any supplemental D or calciferol/D3 supplement. I had by that time been diagnosed with "overlapping malignant neoplasm of pancreas," and must have been taking Creon for pancreatic exocrine insufficiency. This test had been ordered by an NP working out of my PCP's office; she then prescribed Vitamin D3 1,000 unit, to be taken one tablet by mouth one time daily; her comment regarding rationale for the prescription was that my test result was on the low side of normal