Can diet affect blood tests

[66olives]

Hi, I know that taking certain supplements can affect thyroid blood tests, e.g. biotin can supress TSH. Therefore can eating a large portion of biotin rich foods (eg liver or eggs) within 48hrs prior to a thyroid blood test have a similar effect?

[Regenallotment Ambassador]

Good question, I’ve never thought of that. I guess it is down to the mcg ingested, this piqued my interest so I’ve looked it up 😊

Thorne Basic b complex for example has 400mcg biotin in a dose.

An egg contains 10 mcg, beef liver 30.8mcg according to ods.od.nih.gov/factsheets/B...

so I can see why stopping a biotin supplement is a good idea if it has an impact on TSH. 🌱

[Lalatoot in reply to Regenallotment]

The biotin isn't stopped just because of the impact on TSH; it is stopped because it interferes with the testing process used in some of the labs and so all results may be compromised..

[Regenallotment Ambassador in reply to Lalatoot]

I just googled how does biotin impact blood tests. That explains it well 👍 Thanks Lalatoot

[Jaydee1507 Administrator]

In this paper where a biotin supplement was taken and its effects studied on thyroid function they are talking about fairly large doses of 20mg.

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

Thorne Basic B or similar contains 400mcgs biotin which is obviously quite a bit less but to be on the safe side its recommended to stop taking it 4-7 days prior to test.

Food has even less as Regenallotment has kindly looked up at 10mcgs for an egg and 30.8mcgs for beef liver so I think in terms of a normal diet where you're not eating these things to the exlusion of all else (which is unlikely!) it's a low amount and should not interfere with your thyroid blood test.

[66olives]

Thanks everyone.

I will have a read and at last satisfy my curiosity into why it certain things interfere with the results.

It's a fascinating subject.