Strange Vitamin D Results from Medichecks

[jenny876]

Hello, Ive just been looking through my Vitamin D results from Medichecks - they are as follows:

18th August 2023 49.9nmol/L (50-250)

5th September 2023 75nmol/L (50-200)

That is a huge jump in a couple of weeks and I wasnt taking Vitamin D at this time. I also had tests done at Randox:

30th September 2023 74nmol/L (50-375)

My recent resuts from Medichecks show Vit D at 43.1nmol/L (50-250).

Would appreciate any thoughts! Thanks

[TiggerMe]

We had some lovely sunny weather at the end of last summer and if you haven't been supplementing over winter it looks believable

[jenny876 in reply to TiggerMe]

Im indoors most of the time as unwell so never get the sunshine - this wouldve been the case last Sep/Aug too.

[TiggerMe in reply to jenny876]

Ideally looking to get it in the 100-150 range

[Star13]

If I were in your shoes I’d go to the Better You website and order a test from them. They will analyse it and send you the appropriate mouth spray with instructions of how many squarts to use per day. It will be a loading dose to start with and then a maintenance dose.

I use there sprays and got mine up to 100 in quite a short time. I’ll add the link in a moo.

betteryou.com/products/vita...

[FallingInReverse]

All lab tests have a margin of error. It’s impossible for any test to be 100% accurate 100% of the time.

Although….. it’s only your 5th September 2023 75nmol/L (50-200) that’s the outlier at 50%. The rest are between 0-10% ish through range. (I’m guessing your recent Medichecks has a typo (should be 43.1nmol/L 50-250).)

Check my mental math tho. Did it very quickly, but pretty sure you’ve only got that one outlier.

Regards to D test consistency, it looks like the situation is even more layered than the usual margin of error too, as the different kinds of tests used have changed over the years, different labs may use different methodologies, or the same methodology with different interpretations.

Although far more nuanced than this - it’s reasonable to expect 5-10% error rate. That will account for some of the variability.

Per this from an article found on pubmed:

ncbi.nlm.nih.gov/pmc/articl...

The US National Institute for Standards and Technology developed separate serum-based standard reference materials to help minimise inter-method disagreement and reduce bias. ... The first vitamin D standardisation certification program administered by the US Centers for Disease Control and Prevention is now in place. More than eight methods have achieved certification in this program including several automated, commercially available immunoassays. To achieve annual certification, tests must have a bias of ±5% (closeness to the true result) and an imprecision (reproducibility) of 10% or less.

[Batty1]

I had 2 very different Vitamin D tests 2 weeks apart too … not Medichecks but it does make me wonder.

[jenny876 in reply to Batty1]

I know - especially if like me you are trying to up dose as quickly as possible - it could have adverse effects if youre levels are actually higher than results show.

[Batty1 in reply to jenny876]

This is the reason Im waiting to add Vitamin D supps until I retest again in April…. I don’t want to take too much.