Active vs. storage vit. D testing...

[Wendy B]

All the terms and "AKA's" for all the forms of Vitamin D testing are a bit confusing to me and if you are savvy with them I'm requesting your help on just a very specific question: Does my naturopath need to still order the Calcitrol test????

To explain: I recently learned from a fellow Peater that this low result of my Vitamin D from labcorp Nov. 2020 is my inactive form..
"Vitamin D, 25-Hydroxy
17.5 - Low (range 30 - 100)"

He suggested testing my active form my reveal a higher amount so I asked my Naturopath if she would order my active form but she was not familiar with active form of Vit d and told me to look up the labcorp test for it and email it to her and she would order it. I found calcitrol looks like it is the active form and emailed her this link below (please see link).
https://www.labcorp.com/.../calcitriol-1-25-di-oh-vitamin-d.
However, when i went to lab yesterday, they made this printout for me showing me what she ordered and I think all she did was do the same test I had done October 2020 (is this right?)....
They said it was a whole panel and so i had my blood drawn. Looking more closely at it, it looks like it does not contain the calcitrol, right? I emailed her and she emailed back saying it was the right test. Help please? So I still need to have her order the calcitrol right? Nevermind all my scribbled notes on right side of photo. Thank so much!

 

[Mito]

To explain: I recently learned from a fellow Peater that this low result of my Vitamin D from labcorp Nov. 2020 is my inactive form..
"Vitamin D, 25-Hydroxy
17.5 - Low (range 30 - 100)"

Testing 25(OH)D and PTH on the same blood draw is helpful because the reference range for 25(OH)D is set based on maximal suppression of PTH. Chris Masterjohn advocates for a 25(OH)D level that gets you into the lower half of the reference range for PTH. I think Peat prefers the lower quarter of the PTH reference range.

To get the full picture, testing 25(OH)D, PTH, 1,25-dihydroxyvitamin, calcium, phosphorus and maybe even prolactin all on the same blood draw is helpful.

 

[Wendy B]

Testing 25(OH)D and PTH on the same blood draw is helpful because the reference range for 25(OH)D is set based on maximal suppression of PTH. Chris Masterjohn advocates for a 25(OH)D level that gets you into the lower half of the reference range for PTH. I think Peat prefers the lower quarter of the PTH reference range.

To get the full picture, testing 25(OH)D, PTH, 1,25-dihydroxyvitamin, calcium, phosphorus and maybe even prolactin all on the same blood draw is helpful.

I don't know what PTH testing is or what it is for. The reason I was trying to test storage and active d was that someone suggested that even though my storge vitamin D ie - 25 (OH)D is low, that my active D (calcitriol) might be high, as my body may be drawing vitamin d out of my storage and into active form to help fight my Lyme disease, etc. I guess the point being that maybe Im not actually that low in vitamin D but rather that it's jus being used a lot currently. Also there's some question whether im absorbing the D because while I dont supplment with it yet, i do get a lot of sun on my skin in Southern California year round. So why do i need to do this PTH test and all the others? Are these required to help determine what im trying to find out? thanks. Im very ill and very challenged to read or study much at all. thanks for any simple insights on the question i have. thanks

 

[youngsinatra]

Vitamin D is involved in calcium-homeostasis and thus it is useful to test for other calcium-related biomarkers to get a better understanding of what is going on.

PTH is the parathyroid hormone, which elevates if the diet is low in calcium, high in phosphorus or if your 25OHD is low. Besides that there are of course other things that could raise PTH like magnesium deficiency.
PTH is a counter-regulatory stress-hormone, which breaks down bone matter to sustain blood levels of calcium, if dietary calcium is low or calcium absorption is impaired by vitamin D deficiency.

25OHD suppresses PTH, while 1,25OHD increases it. 1,25OHD also rises if calcium intake is low.

I don‘t think that high active D is desirable. And even if you think active D is what you want, you still need the storage D to convert into active D.

 

[Perry Staltic]

It looks l.ike your doctor ordered the wrong test. This is the one you want.

081091: Calcitriol (1,25 di-OH Vitamin D) | Labcorp

Labcorp test details for Calcitriol (1,25 di-OH Vitamin D)

www.labcorp.com

 

[Mito]

I don't know what PTH testing is or what it is for. The reason I was trying to test storage and active d was that someone suggested that even though my storge vitamin D ie - 25 (OH)D is low, that my active D (calcitriol) might be high, as my body may be drawing vitamin d out of my storage and into active form to help fight my Lyme disease

Optimal 25 (OH)D is not generally set based on the 1,25-dihydroxyvitamin level. It’s generally set based on the PTH level. PTH stimulates the kidneys to make more 1,25-dihydroxyvitamin (from 25 (OH)D). PTH and 1,25-dihydroxyvitamin act on bone to pull calcium from the bone into the blood so they can contribute to soft tissue calcification.

You probably don’t want a situation where PTH is above mid range causing 25 (OH)D to be converted heavily into 1,25-dihydroxyvitamin.

 

[Wendy B]

Vitamin D is involved in calcium-homeostasis and thus it is useful to test for other calcium-related biomarkers to get a better understanding of what is going on.

PTH is the parathyroid hormone, which elevates if the diet is low in calcium, high in phosphorus or if your 25OHD is low. Besides that there are of course other things that could raise PTH like magnesium deficiency.
PTH is a counter-regulatory stress-hormone, which breaks down bone matter to sustain blood levels of calcium, if dietary calcium is low or calcium absorption is impaired by vitamin D deficiency.

25OHD suppresses PTH, while 1,25OHD increases it. 1,25OHD also rises if calcium intake is low.

I don‘t think that high active D is desirable. And even if you think active D is what you want, you still need the storage D to convert into active D.

Thank you for this generous explanation. Ok, sounds like it would be helpful to have naturopath do all the tests but not sure i can re-test the one she did last week so soon after and get it covered by insurance

 

[Wendy B]

It looks l.ike your doctor ordered the wrong test. This is the one you want.

081091: Calcitriol (1,25 di-OH Vitamin D) | Labcorp

Labcorp test details for Calcitriol (1,25 di-OH Vitamin D)

www.labcorp.com

Thank you so much. Yep im understanding the calcitriol one is what she shoud have done. thanks

 

[Wendy B]

Optimal 25 (OH)D is not generally set based on the 1,25-dihydroxyvitamin level. It’s generally set based on the PTH level. PTH stimulates the kidneys to make more 1,25-dihydroxyvitamin (from 25 (OH)D). PTH and 1,25-dihydroxyvitamin act on bone to pull calcium from the bone into the blood so they can contribute to soft tissue calcification.

You probably don’t want a situation where PTH is above mid range causing 25 (OH)D to be converted heavily into 1,25-dihydroxyvitamin.

thank you!

 

[Wendy B]

Testing 25(OH)D and PTH on the same blood draw is helpful because the reference range for 25(OH)D is set based on maximal suppression of PTH. Chris Masterjohn advocates for a 25(OH)D level that gets you into the lower half of the reference range for PTH. I think Peat prefers the lower quarter of the PTH reference range.

To get the full picture, testing 25(OH)D, PTH, 1,25-dihydroxyvitamin, calcium, phosphorus and maybe even prolactin all on the same blood draw is helpful.

Question...I'm guessing that for insurance reasons that I can't re-test 25(OH)D for some period of time (not sure how long) since it was just drawn for Labcorp last week. So would it be meaningless to get the others tests, even the calcitriol, drawn at this time? Sounds like maybe I'm going to have to wait a few months or something (?)

 

[youngsinatra]

In my honest opinion. At a level of 17.5ng/ml you most likely will benefit from supplementing vitamin D, despite not having all the tests available yet.

If you want to have a personal calculation for raising your vitamin D, send me a direct message.

 

[Mito]

Question...I'm guessing that for insurance reasons that I can't re-test 25(OH)D for some period of time (not sure how long) since it was just drawn for Labcorp last week. So would it be meaningless to get the others tests, even the calcitriol, drawn at this time? Sounds like maybe I'm going to have to wait a few months or something (?)

If you haven’t started supplementing Vitamin D yet or made any major dietary changes such as increasing calcium significantly, it will still be meaningful since 25(OH)D probably won’t have changed.