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Vitamin B1 (Thiamine)
A water-soluble B vitamin. In your body it becomes thiamine pyrophosphate, a coenzyme for four key enzymes, including the ones that feed glucose into the Krebs cycle and break down branched-chain amino acids. Our file describes it as critical for glucose metabolism and for nerve cells. It carries four authorised EU health claims, EFSA has set no upper limit for it, and it appears in two formulas at two very different doses: 1.1 mg and 100 mg.
WHAT WE ARE ALLOWED TO SAY
Four claims. All of them authorised.
These are the four wordings on the EU register for thiamine, and we do not paraphrase them into something that sounds stronger. All four carry the same condition: the product has to be at least a source of thiamine under Regulation (EC) 1924/2006. Energy & vitality serves 1.1 mg, which is 100% of the NRV. Glucose & metabolism serves 100 mg, about 90 times the NRV.These are the wordings on the EU register for thiamine, and we do not paraphrase them. All four need the product to be at least a source of it. Both of our formulas serve at least 100% of the NRV.
Thiamine is not the headline claim on either of its formulas: that comes from the niacin in Energy & vitality and from the magnesium in Glucose & metabolism, where the blood glucose claim belongs to the chromium next to it. Thiamine has no authorised claim for blood sugar, and 100 mg does not buy it one. The four claims only need a source of thiamine, so the larger amount is not a claim argument and we do not use it as one.
WHICH FORM
Two forms on file. One question still open.
The four claims attach to thiamine, not to a particular salt, so the form is not a claim argument and we do not use it as one. Our file names two acceptable forms, benfotiamine, which is fat-soluble, and thiamine hydrochloride. Glucose & metabolism is marked for benfotiamine at a raised dose. Which of the two goes into Energy & vitality is not recorded yet.
Dissolves in water. Our notes put its absorption at 5 to 10%, and record that absorption saturates, so a larger amount does not raise it in proportion.
The form Glucose & metabolism is marked for, at 100 mg. Our notes describe its absorption as variable and high, without giving a figure, and give 50 to 100 mg as its range.
Our form file marks it as not stable in liquid, and sensitive to light, heat and alkaline pH. It keeps best between pH 3 and 5, and it tastes bitter. How that is handled in a liquid dose 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 thin. Our file gives an average absorption of 8% for the hydrochloride, a half-life of about 1.8 hours and removal through the kidneys. It takes days rather than hours to act, and our file records that it is not significantly broken down by the CYP liver enzymes. Our notes also record the preferred form as not yet settled, even though the form file names one. None of this is an authorised claim.Our file gives an average absorption of 8% for the hydrochloride and a half-life of about 1.8 hours. The preferred form is not fully settled yet. None of this is a claim.
WHERE IT APPEARS
Two of the twenty-nine carry thiamine.
Both in the morning dose, at very different amounts: 1.1 mg with the other B vitamins and coenzyme Q10 in Energy & vitality, and 100 mg as benfotiamine, before breakfast, with chromium, alpha-lipoic acid, cinnamon and magnesium in Glucose & metabolism. Energy & vitality is pending clinical validation, and Glucose & metabolism is still in development. Each has its own exclusions, listed on its page.
THE CEILING
No EFSA limit. No other reference in our file.
EFSA has not set an upper limit for thiamine, and our file carries no other reference figure in its place. Our label notes record it as a high-safety vitamin: rare allergic reactions have been reported only with injected doses, which does not apply to a drop you take by mouth. If both formulas were in your plan on the same morning, your total from us would be 101.1 mg. The engine has no rule written for thiamine yet.EFSA has set no upper limit for thiamine, and our file has no other reference figure. Both formulas together would come to 101.1 mg. The engine has no rule for it yet.
1.1 mg in Energy & vitality is 100% of the NRV, which is also the minimum effective amount in our file. The 100 mg of benfotiamine in Glucose & metabolism sits at the top of the 50 to 100 mg range our notes give for that form. That is a reason to include it, not a permission to promise anything.
Having no upper limit is not the same as being safe at any dose. Without a reference figure, the engine has nothing to check your total against, and we would rather write that down than let the gap look like a green light.
Our file records no contraindication for thiamine itself. Do not go over the recommended daily dose, keep it out of the reach of young children, and do not use it in place of a varied, balanced diet. Rare allergic reactions have been reported with injected thiamine, which our file notes does not apply to oral use. The formulas that carry it add their own exclusions: Energy & vitality is ruled out with liver disease or vitamin K antagonist blood thinners; Glucose & metabolism is ruled out with type 1 diabetes, pregnancy or liver disease. Glucose & metabolism is meant for prediabetes, and our file refers anyone with an HbA1c above 6.5% to an endocrinologist.
WHAT IT REACTS WITH
Documented pairs, not hunches.
Thiamine is one of the 140 ingredients in our library, so it has 139 possible partners. None of them is documented yet as a pair with thiamine, out of the 443 pairs on file, and there is none with medication either.
Chromium, alpha-lipoic acid, cinnamon and magnesium in Glucose & metabolism, the other B vitamins and coenzyme Q10 in Energy & vitality: none of them is in our table as a pair with thiamine. They share a dose by design, but that is a formula decision, not a checked interaction.
Our horsetail notes mention thiaminase, an enzyme that breaks down B1, as a mild risk only in a badly processed preparation, and rule horsetail out for people short of thiamine. No VION formula carries horsetail, and the pair is not in our table yet.
No drug interaction for thiamine is in our drug table, and our file records that it is not significantly broken down by the CYP liver enzymes. Energy & vitality is still ruled out with vitamin K antagonist blood thinners, because of the coenzyme Q10 in it. If you take regular medication, ask a healthcare professional before starting any formula.
Thiamine has no documented pair at all yet, which is not the same as having none. 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.Thiamine has no documented pair yet, which is not the same as having none. 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 B1 (Thiamine) →
140 INGREDIENTS · 64 IN USE TODAY
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