My doctor ordered wrong Vitamin D Test

Today I asked my doctor for Vitamin D test because I am not supplementing but would like to start, and would like to get a baseline first. It turns out she ordered 1,25-dihydroxyvitamin D instead of 25-hydroxyvitamin D. From what I am reading, this is the wrong test and is useless for assessing Vitamin D stores and deficiency/toxicity. Only 25-hydroxyvitamin D can do that. Is that correct? Should I ask for a redo with right test?

Related question: If I start supplementing now with Vitamin D (since so many people seem to think that it's important for Afib protection, Covid protection, osteoporosis protection), and then later am able to take the correct Vitamin D test (25-Hydroxyvitamin D)... How long in advance of test do I need to halt Vitamin D to get accurate blood level rather than level that reflects the supplement I just put in me that morning. Is 24 hours sufficient?



Edited 1 time(s). Last edit at 02/12/2021 06:58PM by PoetKim.

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PoetKim
Related question: If I start supplementing now with Vitamin D (since so many people seem to think that it's important for Afib protection, Covid protection, osteoporosis protection), and then later am able to take the correct Vitamin D test (25-Hydroxyvitamin D)... How long in advance of test do I need to halt Vitamin D to get accurate blood level rather than level that reflects the supplement I just put in me that morning. Is 24 hours sufficient?

This may answer your question.
[www.uspharmacist.com]

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colindo
This may answer your question.
[www.uspharmacist.com]

Thanks colindo. That's interesting. It says: "while calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days." So I take that to mean I would have to halt supplement for long time, more than 15 days, to clear the effects of the supplement from my body before testing for my body's current 'natural' stores of Vitamin D.

I have got a message in to my functional medicine Dr. asking him to order the right Vitamin D test so I can get a baseline on myself before I start supplementing. I think that will be best way to go.

Am printing off that article for my files. It was quite informative in separating out the different types/stages of Vitamin D.

Wow! I'm glad I insisted on getting BOTH Vitamin D tests done instead of just settling for the single one my GP ordered (1,25-dihydroxyvitamin D), which measures the active form of D in the body at that moment but gives no indication as to the body's stores of Vitamin D. I went to my functional medicine doctor for the other test (25-hydroxyvitamin D) that evaluates stores to determine deficiency or overload.

And on that second test (25-hydroxy), I am below normal at 67 nmol/L (ref range: 75-150).

My calcium (done at same time) is 2.31 nmol/L (ref range: 2.10-2.60).

On the first Vitamin D test (1,25-dihydroxy) I was normal at 97 pmol/L (ref: 60-120).

I had not supplemented my D3 for quite a long time because the supp makes me queasy a couple hours later and also somewhat agitated and less 'happy' and tranquil. That effect builds up over days. And even at very low daily doses of 1,000-2,000iu I have that effect from D3. I take mine from eye-dropper in base of extra virgin olive oil. 1 drop=1000iu. If I mix it in oatmeal I don't get nauseous. But it still has the agitating effect on me, cumulative over time. That is always why I end up halting D3. But obviously I need to get back on it somehow!