Biotin (B7) vitamin can effect PSA results

Thanks! Turns out the assay method my lab uses is sensitive to biotin, which is in a quantity sufficient to skew results if taken within 72 hours of getting a psa test. I'll adjust appropriately going forward. Thanks again! Best wishes.

I think it's important to note the operative phrase: CAN INTERFERE.

The reason I mention this is because when I was first diagnosed, based purely on a high PSA that had risen consistently over two years, I wanted to be 1000% sure before I went forward. I researched extensively what can cause a PSA rise and after getting a list of "mights", including certain supplements, sexual activity, riding a bicycle, pumping weights, etc - I asked my doctor to wait 6 weeks and take another PSA test when I abstained from all those things for 6 weeks (long enough to eliminate them as the cause). My doctor told me at that time that it's quite rare that those things have an impact but he had no issue with me trying. I refer to this as when I tried to "game the system" by avoiding all PSA impacting "possibilities". It was quite difficult to abstain from all those things for 6 weeks and, in the end, it made no difference at all and then I charged forward.

It's very easy for us all to grasp at even the slightest hint of any sort of impact on our cancer, and many of those things pop up here - from not eating red meat to not eating any meat to only eating fish or eating copious amounts of broccoli to working out like a crazy man. We have to all be aware that these are all anecdotal for the most part, and the science behind it is very thin.

Don't get me wrong, I'm not saying stuff like this doesn't help, because I also believe the mind is very powerful and if you believe something strong enough that perhaps your body reacts as well. So do those things if you think they will help, but don't get disappointed if they don't work quite as well as you think they will or if they don't work at all.

Even this study shows a very small sample size and the main takeaway seems to be to avoid it only shortly before a PSA test, as it has a 1.8 hour half life. I'm sure there are many other things that can impact PSA's that are similar to this, but until we have tens of thousands of tests we can never be certain.

I mention this because I'm quite guilty of trying these things and while my hopes were not pinned on the outcome, there was some hope and then that's dashed and it's another hit to your emotional state that is already fragile from being told you might have a cancer that, without knowing better, feels like a death sentence because not that long ago it was absolutely one.

Hi @survivor5280 -- I agree with your sentiment that trying to "explain away" a high psa, or using various supplements/diet to try to treat PCa is not a good idea. However, the article surftohealth88 identified above is a very different issue; that the presence of biotin in the blood serum may interfere with an accurate psa test result depending on the level of serum biotin and whether the assay method is using the biotin-streptavidin design. This is simple chemistry for the assay types that depend on this chemistry for measuring psa. I then checked the assay method used for 3 of my last 4 psa tests and it was one that uses the biotin-streptavidin design, so it can report an artificially low psa if biotin supplementation is being taken. I then checked Quest Lab's clinical guidelines, and they suggest abstaining for 72 hours from taking very large doses of biotin before doing blood tests. Although the quantities they cite are much higher than the amount found in my B vitamin supplement (which gave me some degree of comfort), since I'm interested in detecting even minute changes in my psa I'll definitely skip my B vitamin supplement for a couple days before my next psa test. I want that psa number to be as accurate as possible. Best wishes.

@retireditguy

Thanks for clarification what my post was all about. 👍

Our original urologist told us this and it was also mentioned on lab papers before we did PSA before surgery so I wanted members to be aware of the interaction.

I have no idea how this general and important information became a post about using supplementation for lowering PSA 🤔 ? I really hope other members did not see it as such.