The foods richest in vitamin B1 (thiamine) per 100g are yeast extract, wheat germ and seeds such as flax and sunflower, according to USDA FoodData Central. For a normal plate of food, pork is the one to know: 100g of roasted pork tenderloin carries 0.95mg, about 79% of the 1.2mg a day adult men need.
That is the list. What most lists skip is how fragile the numbers are. Roasting, rinsing, milling and a few drinks can each take a large bite out of what reaches you. The ranking below comes first, then the seven things that decide whether those milligrams actually count.
The short version
- Pork tenderloin gives 0.95mg per 100g, roughly 11 times beef sirloin.
- Men need 1.2mg a day in the US and 1mg in the UK.
- Raw sunflower seeds list 1.48mg per 100g. Dry roasted list 0.106mg.
- Enriched white rice carries eight times the thiamine of unenriched.
- Your body cannot store thiamine, so it has to come in daily.
Foods rich in vitamin B1, ranked per 100g
Every figure below is from the USDA's FoodData Central SR Legacy dataset, in milligrams of thiamine per 100 grams. Cooked foods are listed as cooked, because that is how you eat them. Treat each number as a central estimate. Individual products vary, and fortified foods vary the most.
| Food | Thiamine (mg per 100g) |
|---|---|
| Yeast extract spread | 23.4 |
| Wheat germ, raw | 1.88 |
| Flaxseed | 1.64 |
| Sunflower seed kernels, dried | 1.48 |
| Macadamia nuts, raw | 1.20 |
| Pork tenderloin, lean, roasted | 0.95 |
| Pistachios, raw | 0.87 |
| Sesame seeds, hulled | 0.70 |
| Pork loin chop, lean, grilled | 0.66 |
| Ham, sliced | 0.63 |
| White bread (enriched) | 0.53 |
| Oats, dry, unfortified | 0.46 |
| Wholemeal bread | 0.39 |
| Salmon, farmed, cooked | 0.34 |
| Mussels, cooked | 0.30 |
| Green peas, frozen, boiled | 0.28 |
| Black beans, boiled | 0.24 |
| Brown rice, cooked | 0.18 |
| Lentils, boiled | 0.17 |
| Beef sirloin steak, grilled | 0.08 |
| Chicken breast, roasted | 0.07 |
| Egg, hard-boiled | 0.07 |
The bottom three rows are there on purpose. They are the protein foods most men lean on, and none of them is a thiamine food.
1. Pork carries about 11 times the thiamine of beef
This is the single most useful fact on the list. Lean roasted pork tenderloin has 0.95mg per 100g. Grilled sirloin has 0.083mg and roast chicken breast 0.07mg. Same plate size, same protein, more than ten times the B1.
So a man who eats chicken and steak every day and never touches pork can hit his protein target with ease and still come in light on thiamine. Ham counts too, at 0.63mg per 100g for regular sliced ham.
2. Seeds lead the plant list, until you roast them
Dried sunflower kernels list 1.48mg per 100g. The dry-roasted entry in the same database lists 0.106mg, about 7% of the raw figure. They are separate samples, so do not read it as an exact loss rate. Read it as a direction. Thiamine is damaged by cooking heat, and roasted snack seeds are a weaker source than the raw bag.
Flaxseed (1.64mg), macadamias (1.20mg) and pistachios (0.87mg) are all listed raw. A 30g handful of raw pistachios works out at about 0.26mg from those figures. Useful. Nowhere near a day's worth on its own.
3. Yeast extract is the densest food here, at teaspoon doses
The USDA lists yeast extract spread at 23.4mg per 100g. Nobody eats 100g of it. A 5g serving on toast works out at about 1.17mg from that figure, which is close to a full day for a man.
The catch is that brands differ. Some yeast extracts are fortified with B vitamins and some are not, so the label on your jar beats any database row. If yours lists thiamine per serving, trust that number.
4. White bread can beat wholemeal, because of the law
Enriched white bread lists 0.53mg per 100g. Wholemeal lists 0.39mg. Milling removes most of the thiamine from white flour, so it gets added back.
In Great Britain this is a legal requirement. The Bread and Flour Regulations 1998 require at least 0.24mg of thiamin per 100g of flour, added to non-wholemeal flour and naturally present in wholemeal. Wholemeal still wins on fibre. On B1 alone, the white loaf is not the villain people assume.
5. Rice depends on enrichment and on how you cook it
Cooked enriched long-grain white rice lists 0.163mg per 100g. The unenriched version lists 0.02mg. That gap is why thiamine deficiency is most common where polished rice or milled cereal is the staple food. Milling removes most of the vitamin.
Cooking takes more. A 2017 study of fortified rice tested four cooking methods, and the best performer (the microwave) kept 65.4% of the thiamine. Brown rice keeps its bran and lists 0.178mg cooked, with no enrichment needed.
6. Peas, beans and lentils give a steady base
None of the legumes are headline sources per 100g. Frozen peas list 0.28mg, black beans 0.24mg and lentils 0.17mg. They earn a place because people eat them in bigger portions and more often than macadamias. The NHS lists peas first among its good thiamin sources for exactly that reason.
7. Some of what you drink works against what you eat
Tea, coffee, raw fish and shellfish contain thiaminases, enzymes that break thiamine down. Normal coffee intake is not a reason to panic. A diet built on strong tea and very little pork, seed or wholegrain is a different story.
Alcohol is the bigger problem. Chronic heavy drinking is one of the main settings where thiamine deficiency shows up. In rats and human gut cells, chronic alcohol exposure cut the carrier-mediated uptake of thiamine across the intestinal wall. So heavy drinking means less of the thiamine on the plate actually makes it into the body. If that sounds familiar, our piece on vitamin B1 deficiency symptoms covers what running low looks like.
How much thiamine you actually need
The US RDA is 1.2mg a day for men and 1.1mg for women. The NHS sets it at 1mg for men and 0.8mg for women aged 19 to 64. Either way, the numbers are small. A 150g lean pork chop works out at about 0.99mg from the USDA figure, and two slices of enriched bread (about 60g) add roughly 0.32mg from theirs. That covers the day.
The part that matters is the timing. The NHS says thiamin cannot be stored in the body, so you need it in your diet every day. A great Sunday roast does not cover a thin Wednesday.
Where Fireblood fits
Food first. If you eat pork, seeds, legumes and fortified bread across a normal week, your thiamine is probably fine. The gap opens in specific patterns: no pork, mostly chicken and beef, roasted snacks, unenriched rice, and a few too many drinks.
Fireblood contains 12mg of thiamine as thiamine hydrochloride per scoop. That is 10 times the 1.2mg US RDA and well under the 100mg a day the NHS says is unlikely to cause harm. It is there to cover the days the plate does not, alongside the rest of the formula.
We sell a daily vitamin and mineral powder, so weigh this with that in mind. Fireblood carries 12mg of thiamine alongside 38 other ingredients, each one listed with its form and dose on the label. If you would rather cover the gaps in one scoop than track pork chops, see the full formula here.
