Study after study has shown that pretty much most dietary supplements are at best useless, and at worst dangerous. You don’t need to take them unless a clinical practitioner recommends that you do.

Now, according to a bulletin by the Food and Drug Administration (FDA), Vitamin B7 supplements – commonly known as biotin – could be skewing lab tests and indirectly putting people in harm's way.

“The FDA is alerting the public, health care providers, lab personnel, and lab test developers that biotin can significantly interfere with certain lab tests and cause incorrect test results which may go undetected,” the agency explains in a statement.

“Biotin in patient samples can cause falsely high or falsely low results, depending on the test. Incorrect test results may lead to inappropriate patient management or misdiagnosis,” it notes, going on to add that they’ve identified at least “one death related to biotin interference in lab tests.”

They’re warning the public, health care providers, those that work in scientific laboratories, and industry workers to be aware of this before conducting any experiments or ingesting large quantities of the supplement.

Biotin doesn’t just come in one single pill. It’s found in a range of multivitamins and a variety of supplements. This water-soluble B-vitamin may help those with a genuine deficiency – in which it helps prevent hair thinning or skin rashes – but most people that take it are perfectly healthy, and hope that it will make their hair, skin, and nails look better.

The daily recommended allowance for biotin is 0.03 milligrams, which would only very rarely interfere with lab tests. However, common biotin supplements contain 667 times that amount. The FDA also note that “physicians may recommend up to 300 milligrams per day for conditions such as multiple sclerosis” – a 10,000 percent jump.

Plenty of laboratory tests use biotin in their experiments because it’s able to bind to specific proteins, allowing them to pick up on certain health conditions, particularly those involving the cardiovascular system. If the researchers are unaware that the test subject already takes a ludicrously high amount of biotin as it is, it can lead to false data and, as aforementioned, health risks.

Most of you reading this will be consumers, not researchers. The FDA’s advice to you, then, is to educate yourself. Find out if any supplements you use contain biotin; if you think of taking it, contact your doctor first. If you have a medical test coming up, then make sure you’re aware of how much biotin you’re actually taking and let the relevant parties know.

Around 23,000 emergency hospital visits in the US every year are attributed to adverse effects of dietary supplements. If you think you need them, trust us – you probably don’t.

[H/T: Gizmodo Australia]