Skip to content
TBESBY
Language: EN

Research & Insights

B Vitamins in Dried Brewer's Yeast: Thiamin, Riboflavin, Niacin and What They Mean for Feed and Pet Food

Published

TBESBY Inactive Dried Brewer's Yeast, a light brown, free-flowing powder

In short: Published feed tables list dried brewer's yeast at about 85 mg/kg thiamin, 40 mg/kg riboflavin and 445 mg/kg niacin as fed. Values vary between sources and lots. At 1 to 5% inclusion, brewer's yeast can cover a useful share of FEDIAF and NRC thiamin and niacin minimums before processing. Heat and storage reduce thiamin from any source, so formulators should work from lot values on the certificate of analysis (CoA).

Why do nutritionists look at brewer's yeast for B vitamins?

Brewer's yeast is the Saccharomyces cerevisiae biomass left after beer fermentation. Feedipedia describes it as mainly a protein source that also supplies B-complex vitamins, nucleic acids and minerals. In the Feedipedia tables, dehydrated brewer's yeast averages 48.9% crude protein on a dry matter basis, across 108 samples.

For poultry, Feedipedia notes that brewer's yeast is used mostly for its B-complex vitamins, usually at 2 to 5% of the diet. In pet food, it adds protein and flavour as well as B vitamins. Our brewer's yeast nutrient profile covers protein and amino acids. This article focuses on thiamin (vitamin B1), riboflavin (B2) and niacin (B3), with the other B vitamins listed for reference.

How much thiamin, riboflavin and niacin does dried brewer's yeast contain?

The INRA-CIRAD-AFZ feed tables (Feedtables) give one of the most complete published vitamin profiles for dried brewer's yeast. Table 1 shows those values next to a recent laboratory analysis of a commercial brewer's yeast.

NutrientUnitFeedtables, as fed (92.8% DM)Feedtables, dry matterDainton et al. 2022, dry matter (5 lots)
Thiamin (B1)mg/kg84.991.536.8 ± 5.97
Riboflavin (B2)mg/kg39.542.5not reported
Niacin (B3)mg/kg445480not reported
Pantothenic acid (B5)mg/kg110119not reported
Pyridoxine (B6)mg/kg33.536.1not reported
Folic acidmg/kg10.411.2not reported
Biotinmg/kg1.11.2not reported
Vitamin B12µg/kg7.47.98not reported
Cholinemg/kg3,3163,574not reported

Table 1. Published B-vitamin values for dried brewer's yeast. Feedtables values are table averages. Dainton et al. (2022) analysed a spray-dried brewer's yeast.

Two points stand out. First, table values are averages, not guarantees. Second, values vary between sources, processes and lots. Dainton and colleagues measured 36.8 mg/kg thiamin on a dry matter basis across five lots of a spray-dried brewer's yeast.

The practical message is simple. Use table values for early screening. Use lot values from the CoA for final formulation.

What are the thiamin, riboflavin and niacin minimums for dogs, cats and poultry?

The FEDIAF Nutritional Guidelines (July 2024 edition) set recommended minimum levels per 100 g of dry matter. For an adult dog at a maintenance energy intake of 95 kcal per kg body weight to the power 0.75, the minimums are 0.25 mg thiamin, 0.69 mg riboflavin and 1.89 mg niacin. For an adult cat at 75 kcal per kg body weight to the power 0.67, they are 0.59 mg thiamin, 0.42 mg riboflavin and 4.21 mg niacin.

Cats need more than twice as much thiamin per 100 g dry matter as dogs. This is why thiamin gets close attention in cat food. FEDIAF bases its B-vitamin minimums on bioavailable forms at the point of consumption. In practice, the minimum applies to the finished food after processing and storage, not to the formula sheet.

For poultry, University of Missouri Extension guide G8352 reproduces the NRC tables (1984 edition). It lists broiler requirements of 1.8 mg/kg thiamin, 3.6 mg/kg riboflavin and 27 mg/kg niacin from 0 to 3 weeks, for a diet with 3,200 kcal ME/kg. For laying hens it lists 0.8 mg/kg thiamin, 2.2 mg/kg riboflavin and 10 mg/kg niacin. These values are per kg of diet.

What does a 1 to 5% inclusion contribute? A worked estimate

An ingredient's contribution is its inclusion rate multiplied by its nutrient content. Here is the thiamin example for an adult dog food, using the Feedtables dry matter value. This is an estimate, not a guarantee.

  • Yeast thiamin: 91.5 mg/kg DM, which equals 9.15 mg per 100 g DM of yeast.
  • At 3% inclusion on a dry matter basis: 9.15 × 0.03 = 0.27 mg thiamin per 100 g diet DM.
  • FEDIAF adult dog minimum: 0.25 mg per 100 g DM.
  • Share of the minimum: 0.27 ÷ 0.25 = about 110%.

Run the same steps with the Dainton value of 36.8 mg/kg DM and the result at 3% falls to 0.11 mg per 100 g DM, or 44% of the dog minimum. Table 2 runs both values across 1, 3 and 5% inclusion.

Nutrient and reference minimumYeast value used1% inclusion3% inclusion5% inclusion
Thiamin, adult dog (FEDIAF 0.25 mg/100 g DM)Feedtables 91.5 mg/kg DM0.09 mg (37%)0.27 mg (110%)0.46 mg (183%)
Thiamin, adult dog (FEDIAF 0.25 mg/100 g DM)Dainton 36.8 mg/kg DM0.04 mg (15%)0.11 mg (44%)0.18 mg (74%)
Thiamin, adult cat (FEDIAF 0.59 mg/100 g DM)Feedtables 91.5 mg/kg DM0.09 mg (16%)0.27 mg (47%)0.46 mg (78%)
Thiamin, adult cat (FEDIAF 0.59 mg/100 g DM)Dainton 36.8 mg/kg DM0.04 mg (6%)0.11 mg (19%)0.18 mg (31%)
Riboflavin, adult dog (FEDIAF 0.69 mg/100 g DM)Feedtables 42.5 mg/kg DM0.04 mg (6%)0.13 mg (18%)0.21 mg (31%)
Niacin, adult cat (FEDIAF 4.21 mg/100 g DM)Feedtables 480 mg/kg DM0.48 mg (11%)1.44 mg (34%)2.40 mg (57%)
Thiamin, broiler 0 to 3 weeks (NRC 1.8 mg/kg diet)Feedtables 84.9 mg/kg as fed0.85 mg/kg (47%)2.55 mg/kg (142%)4.25 mg/kg (236%)
Niacin, broiler 0 to 3 weeks (NRC 27 mg/kg diet)Feedtables 445 mg/kg as fed4.45 mg/kg (16%)13.35 mg/kg (49%)22.25 mg/kg (82%)

Table 2. Estimated contribution of dried brewer's yeast to selected minimums. Estimate only. Pet rows are mg per 100 g diet dry matter; poultry rows are mg per kg diet. Percentages show the share of the minimum. Figures exclude processing and storage losses and the vitamins supplied by other ingredients.

The table shows where brewer's yeast does the most work. Thiamin and niacin contributions can be large in dog and poultry diets at 3 to 5%. Riboflavin contributions are smaller. Cats have the highest thiamin minimum, so cat formulas usually combine yeast with the vitamin supplement already in the specification. Treat brewer's yeast as a contributor you can count, at a verified value, and keep your full vitamin specification in place.

Does yeast thiamin survive extrusion and retort?

Thiamin loses activity under heat and during storage, whatever its source. Two studies from Kansas State University give practical numbers.

Retort for wet pet food

Dainton et al. (2022) retorted canned cat foods at a target of 123°C with a 63-minute cook cycle. The diet with brewer's yeast and no added synthetic vitamins lost 45.8% of its thiamin. That was the lowest relative loss of all the treatments. The diet with a standard vitamin supplement and no yeast lost 60.2%. The authors concluded that yeast thiamin did not show better thermal stability than thiamin mononitrate, but that yeast ingredients with similar losses can still add value. Our guide to brewer's yeast in wet pet food and retort covers the process side in more detail.

Extrusion and storage for dry pet food

Mooney (2014), in a conference abstract, tested extruder screw speeds of 350 and 450 rpm and two dryer settings: 104°C for 6 minutes or 127°C for 10 minutes per pass. Retention of the vitamins studied, including thiamin, did not differ between these settings. Storage was the larger risk. At 50°C and 75% relative humidity, an accelerated condition, thiamin fell by 85.86% over 18 weeks. The author noted that vitamin levels in extruded pet diets must account for these changes.

For a formulator, four steps follow:

  • Set the thiamin target on the finished, processed food, not on the formula sheet.
  • Measure thiamin before and after processing on pilot batches.
  • Add a storage allowance that matches the product's shelf life and storage climate.
  • Count yeast thiamin at its CoA value, minus your measured loss factor.

How should buyers specify and verify B vitamins in brewer's yeast?

A brewer's yeast specification usually lists proximate values. TBESBY Inactive Dried Brewer's Yeast, for example, is specified at 40 to 46% crude protein, moisture below 10%, ash below 6%, fat max 0.5%, fibre max 1.5% and lysine 30.5 g/kg. TBESBY does not publish vitamin values for this product. Buyers who want to count B vitamins in a formula should request them on the CoA.

When you ask any supplier for B-vitamin data, cover these points:

  • Name the vitamins you need: thiamin, riboflavin and niacin as a minimum, plus pantothenic acid, B6 or folic acid if they matter to your formula.
  • Ask for results in mg/kg, and state whether they are as fed or dry matter. Ask for moisture on the same report so you can convert.
  • Ask the laboratory to name its analytical method and accreditation, so your own laboratory can repeat the test the same way.
  • Ask for results from several lots, so you can see the spread before you set a formula value.
  • Confirm whether the product contains any added vitamins. A plain brewer's yeast and a yeast with added synthetic vitamins can look alike on a short specification sheet.
  • Repeat the check at set intervals, for example when you renew a contract or change shelf-life assumptions.

Our guide on how to read a brewer's yeast CoA explains each line of a typical certificate.

Where does TBESBY Inactive Dried Brewer's Yeast fit?

TBESBY Inactive Dried Brewer's Yeast is made from fresh brewer's yeast from international breweries in Vietnam. We drum-dry it at our own facilities in Vietnam. The process runs from receiving to drum drying, milling and sieving, packing and laboratory testing. The product has a 12-month shelf life and ships in 25 kg bags or 600 to 1,200 kg jumbo bags. It is U.S. FDA registered, produced under ISO 22000:2018 and non-GMO. See the product page for the full specification, or read how brewer's yeast is used in pet food and for poultry.

To discuss specifications, or to request a CoA with B-vitamin results for your formulation work, contact our team. Tell us your species, inclusion rate and the vitamins you need reported.

Frequently asked questions

Can brewer's yeast be the only thiamin source in cat food?

Not on its own at typical rates. Using Feedtables values, a 5% inclusion supplies an estimated 78% of the FEDIAF adult cat minimum before processing, and retort or storage losses reduce that further. Count yeast thiamin as a contribution and keep a synthetic thiamin source in the specification.

Should I use as fed or dry matter values?

Match the basis of your reference. FEDIAF minimums are per 100 g dry matter, so use dry matter yeast values. The NRC poultry values in the Missouri guide are per kg of diet, so use as fed values. To convert as fed to dry matter, divide the as fed value by the dry matter fraction.

Why do published thiamin values for brewer's yeast differ so much?

Feedtables lists 91.5 mg/kg on a dry matter basis, while Dainton et al. (2022) measured 36.8 mg/kg across five lots of one spray-dried yeast. Sources differ in samples, processes and methods. This is why lot data on the CoA matters more than any single table.

Is dried brewer's yeast the same as nutritional yeast?

No. They are different products, and some yeast products carry added synthetic vitamins. Check the label and the CoA before you count any vitamin in a formula. Our article on brewer's yeast vs nutritional yeast explains the differences.

Sources