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Ingredient file // Vitamin or mineral

Thiamine Mononitrate

A tiny B1 addition with a real job

Thiamine mononitrate is a manufactured form of vitamin B1 added in small amounts to dog food. It helps the finished food meet a dog's B1 needs, which matter for using food for energy and keeping the nervous system working normally.

What it is
A crystalline form of vitamin B1 used to raise the thiamine content of food.
Made from
Thiamine hydrochloride and nitric acid
Main job
Adds vitamin B1
Typical amount
Not published
Watch for
Processing can lower finished B1
Not the same as
Thiamine hydrochloride

Our read // In our catalog

In 1 of every 3 foods we track

Share of foods that list it

36%

933 of the 2,595 foods with an ingredient list on file, from 50 brands. 678 dry dog food, 224 wet dog food, 17 frozen dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 34. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

2%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 98% of foods.

Price per lb

Foods with it $2.93
All foods $3.23

Median of the cheapest bag price across 605 priced foods, 9% below the catalog. The price is the food's, not the ingredient's.

Who leans on it

16%

of the foods that list it are from Blue. 50 brands use it in total.

The story

How vitamin B1 went from rice mystery to recalls

Thiamine's story starts with chickens. After returning to Java in 1887 as a Dutch medical officer, Christiaan Eijkman saw that birds fed polished rice bought for the army developed polyneuritis resembling beriberi. When their feed switched to regular rice with its silver outer layer, they recovered. Eijkman concluded that feed carried an agent that could prevent or cure the disease. He won the 1929 Nobel Prize, and in 1936 Robert Williams first synthesized thiamine, making factory-made B1 possible.10

Thiamine mononitrate is the dry, crystalline salt of that synthetic vitamin. In a rule published December 9, 1983, FDA affirmed it as generally recognized as safe for human food, used as a nutrient supplement at levels set by good manufacturing practice. Dog food uses it for the same job: topping up a vitamin that cooking heat wears down.2,4

The newest turning point came in 2026. On February 17, Go Raw LLC began a recall over low thiamine. In a March 13 advisory, FDA said 8 lots of Quest Cat Food it tested held anywhere from no detectable thiamine to 0.85 mg per kg, far under the 5.6 mg cat minimum. On June 8 the recall grew to a Steve's Real Food chicken recipe sold for cats and dogs. The company said B1 test results vary even in foods formulated with extra.11,12

What it is

How it is made

Vitamin makers synthesize thiamine and convert it into mononitrate crystals. Dog food makers add the concentrated powder through a vitamin premix so a small, measured amount of B1 enters the recipe.2,3,4

  1. 01 // Source Thiamine hydrochloride Manufacturers start with another manufactured form of vitamin B1, thiamine hydrochloride.
  2. 02 // Process Dissolved The hydrochloride form is dissolved in an alkaline solution before its salt form is changed.
  3. 03 // Process Nitrate added Nitric acid makes thiamine mononitrate separate from the solution as crystals.
  4. 04 // Output B1 crystals The crystalline powder is blended into a vitamin premix for food production.

What is in it

Composition, dry matter

81

% active B1

Pure mononitrate supplies about 0.81 gram of thiamine per gram. That conversion matters when a manufacturer calculates how much B1 to add.

Active thiamine 81%6
Thiamine mononitrate 99.7-100%3
Sulfated ash 0-0%3

Active thiamine is part of the mononitrate salt, not an additional ingredient. The purity and ash ranges describe batches from one additive supplier, so they do not describe every product sold.3,6

Why it is in the bag

What the manufacturer gets

  1. 01

    Meets the B1 target

    Dogs must get thiamine from food. A measured addition helps a recipe meet the finished food requirement for normal metabolism and nervous system function.2,5

  2. 02

    Allows for cooking losses

    Heat can lower thiamine in a recipe. Manufacturers may add extra before cooking, then account for what remains in the finished food.2,5

  3. 03

    Fortifies at scale

    The finished food target is measured in milligrams per kilogram. A vitamin premix lets a plant distribute that small amount through a much larger batch.2,3,5

How much AAFCO specifies at least 2.25 mg of thiamine per kg of finished dog food on a dry matter basis; the mononitrate addition varies by recipe.5

Our read // The claims

What the evidence supports

Strong: controlled studies in dogs agree. Some: small or mixed dog data. Thin: mechanism or lab work only. None: nothing, or the evidence points the other way.

  1. Brands say

    Added B1 supports normal metabolism and nerves

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    In a 5-dog case series, B1-deficient meat was linked to neurologic disease, and 2 adult dogs improved with thiamine treatment. Adequate B1 matters; the cases did not test mononitrate against another B1 source.1,2

  2. Brands say

    Added B1 covers losses from cooking

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    AAFCO warns that processing may destroy up to 90% of a diet's thiamine. A veterinary review describes adding synthetic thiamine before cooking, but losses vary by recipe and process. The ingredient listing cannot prove the finished amount.2,5

  3. Brands say

    This B1 form stays stable in kibble

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    Supplier tests reported 97 to 107% mononitrate recovery in pelleted feed after 3 months at room temperature. That supports stability in the tested pellets, but pellets are not extruded kibble and the result is not a shelf life guarantee.3

  4. Owners say

    Extra B1 gives healthy dogs more energy

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    The 5-dog case series concerned deficiency and treatment, not an energy boost in adequately fed dogs. B1 is needed to use food for energy, but extra B1 has not been shown to improve a healthy dog's stamina.1,2

  5. Owners say

    The nitrate makes this ingredient dangerous

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    Nitrate is part of this vitamin salt's chemical form. In a 2025 feed additive review, EFSA judged thiamine mononitrate safe for target animals. Its name alone is not evidence of a harmful nitrate dose.3,4

The research

Studies worth knowing

Published research we read for this page, dog studies first.

  1. 1981 // Controlled feeding trial

    B1-starved beagle puppies stopped eating, then developed nerve disease8

    23 beagle puppies, 2 to 5 months old

    Found. Puppies fed a ration with almost no thiamine ate less and stopped growing for about 58 days on average. Then 8 of 11 developed a neurologic syndrome with seizures and weakness, and 3 others had a sudden death syndrome.

    What it means. Lost appetite and stalled growth came weeks before nerve signs, so an early B1 shortfall could be mistaken for poor appetite.

  2. 1986 // Feeding trial, brain exam

    Long B1 shortage damaged gray matter in puppy brains9

    22 beagle puppies, 2 to 5 months old

    Found. After a mean of 84 days (range 32 to 134) on a thiamine-deficient ration, 8 of 11 deficient puppies had brain lesions, mostly in gray matter. The damage progressed from spongy tissue changes to tissue death. Controls received weekly thiamine injections.

    What it means. Prolonged B1 shortage injures the brain itself, not just appetite, so steady daily intake from a complete food matters.

Straight answers

What owners ask

  1. Q01

    Is it just filler?

    No

    It supplies vitamin B1, which dogs must get from food. Its amount is small because the dietary target is small. It has a specific nutritional job.2,5

  2. Q02

    Why is it near the end?

    Tiny dose

    Ingredients are listed by weight, and B1 is needed in milligram amounts per kilogram of food. A place near the other added vitamins is expected.5,7

  3. Q03

    Does nitrate mean preservative?

    No

    Here, nitrate names part of the thiamine salt. The ingredient is added to supply vitamin B1, not to preserve the food.3,4

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Blue 148
  2. Nulo 80
  3. Wellness 73
  4. Nutro 69
  5. Stella & Chewy's 68
  6. Cesar 32
  7. Bil-Jac 30
  8. Diamond 30
  9. Health Extension 27
  10. Horizon 25

Plus 40 more brands.

Amazon best sellers that list it

  1. #1 Blue Life Protection Formula Adult Chicken and Brown Rice Recipe Dry Dog Food
  2. #5 Blue Life Protection Formula Adult Small Breed Chicken and Brown Rice Recipe Dry Dog Food
  3. #7 Stella & Chewy’s Marie’s Magical Dinner Dust Cage-Free Chicken Recipe Freeze-Dried Raw Dog Food Topper
  4. #8 Diamond Naturals Skin & Coat Formula All Life Stages Salmon & Potato Formula Dry Dog Food
  5. #12 Pedigree Adult Grilled Steak & Vegetable Flavor Dry Dog Food
  6. #17 Taste of the Wild High Prairie Canine Recipe with Roasted Bison & Roasted Venison Dry Dog Food
  7. #22 Cesar Filet Mignon Flavor & Spring Vegetables Garnish Dry Dog Food
  8. #27 Blue Life Protection Formula Senior Chicken and Brown Rice Recipe Dry Dog Food

Rank on Amazon's dog food best seller list, checked October 2026.

Usually listed with, share of the foods that list it

  1. Chicken 41%
  2. Chicken Fat 38%
  3. Flaxseed 37%
  4. Peas 36%
  5. Chicken Meal 34%
  6. Natural Flavor 31%
  7. Brown Rice 20%
  8. Oatmeal 20%
  9. Barley 17%
  10. Dried Plain Beet Pulp 16%
  11. Sweet Potatoes 16%
  12. Lentils 15%

Our read // On the bag

Read it as fortification, then check the diet

Expect thiamine mononitrate near the end of the ingredient list with the other vitamins. Check that the bag says the food is complete and balanced for your dog's life stage. The ingredient name tells you B1 was added; it does not tell you how much survived processing.

Sources

What we read

Checked September 1, 2026.

  1. 1 Thiamine deficiency in dogs due to the feeding of sulphite preserved meat Australian Veterinary Journal, 2005 // Journal
  2. 2 The Role of Thiamine and Effects of Deficiency in Dogs and Cats Veterinary Sciences, 2017 // Journal
  3. 3 Assessment of the feed additives thiamine hydrochloride (3a820) and thiamine mononitrate (3a821) (vitamin B1) for all animal species for the renewal of their authorisation (Kaesler Nutrition GmbH) EFSA Journal, 2025 // Journal
  4. 4 21 CFR § 184.1878 - Thiamine mononitrate Legal Information Institute, Cornell Law School, n.d. // University
  5. 5 AAFCO DOG FOOD NUTRIENT PROFILES AAFCO, 2013 // Regulator
  6. 6 Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs FEDIAF, 2025 // Industry
  7. 7 Reading Labels AAFCO, n.d. // Regulator
  8. 8 Experimentally induced thiamine deficiency in beagle dogs: clinical observations American Journal of Veterinary Research, 1981 // Journal
  9. 9 Experimentally induced thiamine deficiency in beagle dogs: pathologic changes of the central nervous system American Journal of Veterinary Research, 1986 // Journal
  10. 10 Christiaan Eijkman (1856 - 1930) Journal of Neurology, 2018 // Journal
  11. 11 FDA Advisory: Certain Lots of Quest Cat Food Pose Serious Health Risks Due to Extremely Low Levels of Thiamine U.S. Food and Drug Administration, 2026 // Regulator
  12. 12 GO Raw LLC. Expands Voluntary Recall to Include One Lot of Steve's Real Food Freeze-Dried Chicken Recipe Due to Low Thiamine (Vitamin B1) Levels U.S. Food and Drug Administration, 2026 // Regulator
An ingredient on its own tells you very little. What matters is how much of it there is and where it sits in the list. That is why we weigh the top five rather than reacting to any single name further down. Back to the wiki

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