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Biotin
A water-soluble B vitamin, also called vitamin B7 or vitamin H. Your body attaches it to five enzymes that it needs to make glucose and fatty acids and to break down some amino acids. It carries seven authorised EU health claims, EFSA has set no upper limit for it, and it sits at 100 µg in one formula. The main risk our file records is not in your body but in the lab: it can distort some blood tests.
WHAT WE ARE ALLOWED TO SAY
Seven claims. All of them authorised.
These are the wordings on the EU register for biotin, and we do not paraphrase them into something that sounds stronger. All seven carry the same condition: the product has to be at least a source of biotin under Regulation (EC) 1924/2006. Our one formula serves 100 µg, which is 200% of the NRV of 50 µg.These are the wordings on the EU register for biotin, and we do not paraphrase them. All seven need the product to be at least a source of it. Our formula serves 200% of the NRV.
Biotin has no authorised claim for nails, however often you read otherwise. In Skin, hair & nails, the nails claim comes from the zinc next to it, not from the biotin. Our own notes rate the evidence for hair and nails in people who are not deficient as weak, and a real deficiency as rare. Our file also holds a phase 3 trial of high-dose biotin in progressive multiple sclerosis that came back negative. We use it at 100 µg, for the claims above, and for nothing more.
WHY D-BIOTIN
There is only one form that works.
The seven claims attach to biotin, not to a particular form, so the form is not a claim argument and we do not use it as one. Our notes name D-biotin as the only active form of the vitamin, and our form file records the synthetic version as bioequivalent to the biotin in food.
The only active form, according to our notes, and the one our form file marks as preferred. The synthetic version is recorded as bioequivalent to the natural one, with absorption put at 100% at normal doses. That is a note we record, not a claim.
Our form file marks it as stable in liquid and neutral in taste, and it keeps best between pH 4 and 7. It dissolves poorly in water, at around 0.22 g per litre, a little better when the liquid is less acidic. Every VION dose is a liquid, so that is what the choice turns on.
Our file lists both as sensitivities. How that is handled between production and your cartridge is not documented yet, and we would rather write that down than leave it out.
Our figures on how it behaves in your body are short but consistent. Our file puts its absorption at 100% at normal doses and its half-life in the blood at about 2 hours, and your kidneys clear it, as biotin and a breakdown product called bisnorbiotin. It is not significantly broken down by the CYP liver enzymes. It takes weeks to act, and our notes say three to six months before you would see anything in hair or nails. None of this is an authorised claim.Our file puts its absorption at 100% at normal doses and its half-life at about 2 hours. It takes weeks to act, three to six months for hair or nails. None of this is a claim.
WHERE IT APPEARS
One of the twenty-nine carries biotin.
It is 100 µg in the morning dose of Skin, hair & nails, next to vitamin C, zinc, silicon, hydrolysed collagen and hyaluronic acid. That formula is still pending clinical validation, and it has its own exclusions, listed on its page.
THE CEILING
No EFSA limit. The risk is in the lab.
EFSA has not set an upper limit for biotin: in 2014 it found no documented toxicity. The most conservative reference in our file is the German BfR's proposed maximum for a food supplement, 180 µg a day, and our 100 µg stays under it. Our notes also set a working cap of 1 mg a day, added up across everything you take, and 5 mg as an absolute top with a label warning. That cap is not about toxicity, it is about keeping blood tests readable, and it is not written as a rule in the engine yet.EFSA has set no upper limit for biotin. The German BfR reference is 180 µg a day for a supplement, and our 100 µg stays under it. The real risk is a distorted blood test.
100 µg is 200% of the NRV of 50 µg. EFSA's adequate intake for adults is 40 µg a day, and our notes put the usual maintenance amount at 30 to 100 µg a day. That is a reason to include it, not a permission to promise anything.
Biotin can distort tests that rely on biotin and streptavidin: TSH, free T4, T3, troponin, vitamin D, hCG, cortisol, PTH and reproductive hormones, reading falsely high or falsely low depending on the test. Our notes say a single 10 mg dose interferes for at least 24 hours. Stop it at least 72 hours before any blood test, 7 days if you take more than 10 mg a day, and tell the laboratory. Our notes tie the EFSA-recommended label warning to doses from 1 mg, but the formula file flags interference from 30 µg a day, so we give you the warning at 100 µg too.
Because the FDA has identified this risk, check with a healthcare professional before you start. If you have a thyroid condition or your TSH is monitored, stop it at least 72 hours before each check. If you have heart disease, biotin can make a troponin result read falsely low and hide a heart attack: if one is ever suspected, tell the team treating you, and stop it before any urgent heart evaluation. Before any urgent hormone or heart test, stop it 72 hours ahead, or 7 days if your dose is above 10 mg. If you are pregnant or breastfeeding, our file considers it safe at the adequate intake but says to avoid more than 1 mg a day without a clinical reason. Under 18, our file considers it safe at an intake adjusted for age, and it records no contraindication with liver or kidney disease, blood thinners or cancer. The formula that carries it adds its own exclusion: Skin, hair & nails is ruled out if you take a vitamin K antagonist blood thinner, a rule that comes from its vitamin C, not from the biotin.
WHAT IT REACTS WITH
Documented pairs, not hunches.
Biotin is one of the 140 ingredients in our library, so it has 139 possible partners. We have documented three of them, out of the 443 pairs on file, and none with medication. Two of the three are about binders in your gut that keep it from being absorbed.
Both bind biotin in the gut. Charcoal can cut how much you absorb by 30 to 90%, so it never shares a dose and stays at least 3 hours away. White clay stays at least 2 hours away. No VION formula carries either, so this matters if you take them separately.
Both are taken up by the same carrier in your gut. At nutritional doses, up to 100 µg of biotin and 10 mg of B5, the competition does not matter and they can share a dose. Only with biotin from 1 mg and B5 from 100 mg would the engine keep them 2 hours apart. Our notes say alpha-lipoic acid uses the same carrier too, but that pair is not in our table yet.
No drug pair for biotin is in our drug table yet. Our ingredient notes list anticonvulsants (carbamazepine, phenytoin, phenobarbital, primidone) as a major interaction: they speed up how fast biotin is broken down and lower how much you absorb. Long courses of antibiotics may reduce the biotin made by your gut bacteria, and isotretinoin may lower its levels, both on weak evidence. If you take any of these, talk to your doctor before starting a formula that carries it.
Its five partners in Skin, hair & nails, vitamin C, zinc, silicon, hydrolysed collagen and hyaluronic acid, are not in our table as pairs with it yet. Our notes also record that raw egg white binds biotin for good, which cooking the egg removes, but that is not a documented pair either. Across the library, 443 of the 9,730 possible pairs are documented, which is 4.55%. The rest are not "safe", they are simply unchecked, and we would rather write that down than let the number look like a badge.Its five partners in Skin, hair & nails are not in our table as pairs with it yet. Across the library, 443 of the 9,730 possible pairs are documented, which is 4.55%. The rest are not safe, they are simply unchecked.
SOURCES
Everything on this page, with its reference.
Reviewed by VION nutrition team · last reviewed 16 September 2026Read the introduction to Vitamin B7 (Biotin) →
140 INGREDIENTS · 64 IN USE TODAY
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