2 different labs 2 VERY different Vit D levels

[Marnica]

I had my Vit d level (and my son's) done at Quest. Mine was 42 and DS was 44. These levels are decent, but I would like to see our levels in the mid to upper 50's.I had mine redone (paid for it myself) at a more reputable lab (Labcorp) and my level was 72! I joined the grassroots health study for DS and they use ZRT labs and a finger stick. His level from ZRT was 47 (not too different from Quest.

I really do not know what to make of my numbers. I know Quest had serious problems withtheir Vit d accuracy which is why I redid mine, but the discepency is huge and it wasn't for DS...My ND feels 72 is a bit too high (although I have read some sources that say toxicity doesn't start until levels reach 100). I can decrease the amount I am taking, but if my levels are more around 42 I would want to increase them.

How can anyone get a accurate Vit d level so they can properly supplement with so much variations in numbers?????Not sure what to do...I have been just staying on 5,000/day for now. Any advice?

[tanyalynn]

I'm not sure I can help, but can you write out the timeline for the various tests and how much you were supplementing with, and how long the supplementation had lasted beforehand? I don't know if that will help with clarity or not, one thing I was thinking is that maybe the time lag + the Quest problem... though I thought Quest tested higher than was accurate? Something like a third too high? Which makes for an even bigger delta for you. Hmmm...

[subtlycrunchy]

Here's the best article on the how, when, why of vitamin D testing I've come across (from Women to Women)...
To test or not to test — the ABC’s of vitamin D testing and treatment

It doesn't compare Quest with other labs, but do you know which test you had? It says the following:

You want to ask for the test that measures the circulating form of vitamin D: this is referred to as 25[OH]D, or 25-hydroxyvitamin D.

Good luck!

[Marnica]

Originally Posted by subtlycrunchy

Here's the best article on the how, when, why of vitamin D testing I've come across (from Women to Women)...
To test or not to test — the ABC’s of vitamin D testing and treatment

It doesn't compare Quest with other labs, but do you know which test you had? It says the following:

You want to ask for the test that measures the circulating form of vitamin D: this is referred to as 25[OH]D, or 25-hydroxyvitamin D. It's interesting that it says once your optimal level is reached, to just take 2,000iu/day. If it took 5,000 iu/day to reach that level, wouldn't dropping down to 2,000/day result in your bloodlevels dropping as well?

Good luck!

Thanks....great article. Yes I had the 25[OH]D test done at both labs for myself and DS