Vitamin B1 (thiamine)
Vitamin B1, also called thiamine, peaks in our database at ground flaxseed with 1.64 mg per 100 grams, sunflower seeds at 1.48 mg and macadamia nuts at 1.20 mg. The European reference intake comes to 1.1 mg per day (EU NRV). Seeds, nuts and wholegrain cereals are clearly the load-bearing group here.
The role of thiamine, in permitted wording
The authorised wordings in Regulation (EU) No 432/2012 include: "thiamine contributes to normal energy-yielding metabolism", "thiamine contributes to the normal function of the heart" and "thiamine contributes to the normal functioning of the nervous system". Nothing more is listed, so nothing more gets written here. Note the word normal in each of those sentences: they concern maintaining a normal function, not improving performance or resolving complaints.
Where thiamine comes from in our database
The top five per 100 grams: ground flaxseed 1.64 mg, sunflower seeds and pine nuts both at 1.48 mg, macadamia nuts 1.20 mg, shelled pistachios 0.87 mg and sesame seeds 0.79 mg. Oats follow just behind at 0.76 mg. The pattern is strikingly consistent: everything at the top is a seed, a nut or a wholegrain cereal. That is because thiamine sits largely in the germ and bran layer — exactly the part removed when flour or rice is refined.
1.1 mg a day as the reference
The 1.1 mg per day comes from the EU NRV, the same labelling value that drives the percentages printed on packaging. Thiamine is water-soluble and is not stored in any meaningful reserve, so daily supply matters more here than with the fat-soluble vitamins. At the same time the requirement is small in absolute terms: 30 grams of sunflower seeds already covers the reference intake comfortably. Anyone eating oats or wholemeal bread daily gets there without counting.
Situations where intake lags
A low thiamine intake tracks with a heavily refined diet in practice: white bread, white rice, few nuts or seeds. A sustained high alcohol intake plays a part too, and that is a conversation which comes up in our intakes more often than people expect. We draw no conclusion from it and diagnose nothing. If you want certainty about your own values, your GP is the address — not a table on the internet.
Capsule or plate? Where we stand
We recommend no brands and sell nothing, so the question "which B1 should I take" is one we do not answer. What we do inside a coaching programme is shift the base: wholegrain instead of white, a handful of seeds through lunch, oats as a fixed morning building block. That solves several B vitamins at once and delivers fibre and magnesium besides. A capsule does not do the latter, and for someone training five days a week that difference matters.
How we compile this list
We sort every row in the DCRAFT food database on the measured value per 100 grams and take the top of that list. Rows recorded per piece, per slice or per portion do not count, because a value per piece cannot be compared with a value per 100 grams. Products listed under a brand name are left out: their composition changes outside our control, and a ranking resting on it ages without us noticing. Where several products carry precisely the same value, it comes from one shared row in our source data and we name one product from that group. We set this rule out here because a ranking without a visible selection rule is an opinion rather than a measurement.
Frequently asked questions
Which foods contain the most vitamin B1?
Ground flaxseed leads at 1.64 mg per 100 grams, with sunflower seeds at 1.48 mg and macadamia nuts at 1.20 mg.
How much vitamin B1 per day?
Per day the European reference intake counts 1.1 mg (EU NRV). It is a labelling value for adults, not a personal target.
Is thiamine the same as vitamin B1?
Yes. Thiamine is the chemical name used on labels and in claim wordings; in everyday speech people say vitamin B1.
Do you lose thiamine when cooking?
Thiamine is water-soluble and partly leaches into the cooking water. Using that liquid in a soup or sauce keeps more of it than pouring it away.
Sources
- DCRAFT food database — KILLER COACH ENGINE V2.3 workbook (accessed 26 August 2026)
- EU NRV — Regulation (EU) No 1169/2011, Annex XIII (accessed 26 August 2026)
- Regulation (EU) No 432/2012 (accessed 26 August 2026)
Please note: This is general information about nutrition, not medical advice. If you have symptoms or suspect a deficiency, discuss it with your doctor. We do not sell supplements and have no commercial interest in any brand.
Last updated: .
Written by Dennis, founder of Dcraft Of Fitness.