20 Comments
Dec 13, 2022·edited Dec 13, 2022Liked by Chris Masterjohn, PhD

Great and informative article! I had only heard about the TSH test interference. But this is great to know for any future labs. The case of the girl having the surgery is tragic. Look at the dangerous conclusions people can jump to without sufficient knowledge and context of the individual's nutrition.

Also if you made a video on this, I bet it would get a lot of hits. I think on Youtube a lot of vloggers talk about biotin for the skin/hair benefits. But I'm certain they don't know about all these possible effects on their labs that could cause distress. "Taking biotin? Watch out for this!" Thumbnail is someone with nice hair but with a very panicked look on their face, haha.

Expand full comment
author

Thanks, I will make a video at the end of the week. Have crazy consultation/AMA schedule through Thursday.

Expand full comment
Dec 12, 2022Liked by Chris Masterjohn, PhD

Thank you! Good info. I’ve taken 10,000mcg daily for 10 yrs for thinning hair. It does seem to help. My ND said to stop biotin for 4 days before thyroid labs. No mention of any others. Now after reading this, I’m thinking a full week would be more accurate.

Expand full comment
author

A full week is fine to err on the side of caution. 4 days will be sufficient for most people. However, it is for all labs. All of them.

It’s too difficult to try to figure out which labs are biotin-affected. There’s so many it is best to just cut it out before all labs.

Expand full comment
Dec 13, 2022Liked by Chris Masterjohn, PhD

This essay is of major importance and is long overdue. It deserves wide dissemination to, well, any provider who gets labs for their patients. And as so many get their own labs these days... I suppose it would be optimal for all consumers of labs to read this work.

I will do my part to share the knowledge.

Thank You Chris!

Expand full comment
author

Thanks for sharing!

Expand full comment

Why do those of us on a carnivore diet need additional biotin when our ancestors did not?

Expand full comment
author

Where did I say “those on a carnivore diet need additional biotin”?

What is your evidence that your ancestors didn’t eat more biotin than you do?

Expand full comment

The carnivore diet is just an example of a high-protein diet. You said those of us on a high-protein diet probably aren't getting enough biotin and might need as much as 10 times the current US guidelines.

I don't have any evidence of how much biotin our ancestors ate. I was hoping you did.

Expand full comment
author

I went into this in great detail in my high protein article.

I also cover how confused the literature is on the biotin content of foods. I have no idea what our ancestors got because I have deep uncertainty around the biotin content of most foods.

That said, I did not say any high protein diet does not have enough biotin regardless of how it is constructed.

Rather, high protein raises the biotin requirement and most people aren’t getting enough for that.

That article and the Cliff Notes have my biotin rule of thumb for balancing protein with biotin using whole foods.

Expand full comment

I'm a subscriber and read the article and added 4 hard-boiled eggs to my daily routine. But later, I searched it for keywords "ancestors" and "evolution" and didn't find anything on this subject in your article.

If you have deep uncertainty around the biotin content of most foods, why do you think some people aren't getting enough of it?

Expand full comment
author

Because the studies showing we need more were done in people with standard diets showing those aren’t enough.

And there are certain foods like liver and egg yolks that we know are high in it due to correspondence across test methods. There are others that are very uncertain because the different test methods conflict with one another.

I will be doing more research on foods soon.

Expand full comment

Because liver has quite a bit, maybe a high-meat diet with nose-to-tail eating would provide ample biotin.

Expand full comment

Fantastic article Chris! Thank you so much for the countless hours you spend creating these very indepth and thoughtful commentaries.

Expand full comment

Hi Chris. Do you offer consultation for food product development? If so would you please email me at dcampaudio@gmail.com? Thank you!

Expand full comment
author

You can use this and just ignore the health and wellness info:

https://app.acuityscheduling.com/schedule.php?owner=16124930

Expand full comment

This is wild. I am in the medical field and only knew about its TSH lab effects.

Would you withhold lower dosages too such as 0.5 mg or would that be meaningless?

Expand full comment
author

0.5 mg probably should not be a problem if not taken the day of the lab. I would absolutely withhold any biotin the day of the lab regardless of whether it requires fasting.

However you have to keep in mind the situation could be completely altered if someone has impaired kidney function. In that case I would measure serum biotin to characterize the situation. It’s shocking this hasn’t gotten more attention.

Expand full comment
Comment deleted
Expand full comment
author

That’s actually very good to hear, because it means the labs are measuring biotin in the samples at least when they suspect interference, and that they are keeping a close eye in the issue. Much better to get unavailable results back than misleading and false results!

Expand full comment