B Vitamins for Dogs: Why They're Missing from Most Kibble

B vitamins are water-soluble nutrients that dogs need every single day. Unlike fat-soluble vitamins (A, D, E, K) that can be stored in tissues, B vitamins aren't retained long-term. If your dog's diet doesn't provide enough B vitamins daily, deficiency symptoms can develop quickly.

The problem? Most kibble is processed at extremely high temperatures (300-400°F during extrusion), which destroys up to 90% of naturally occurring B vitamins. While manufacturers often add synthetic B vitamins back in, these isolated compounds are far less bioavailable than the naturally occurring B vitamins found in whole foods like organ meats.

This guide covers what B vitamins do, why they're missing from most commercial foods, and the best whole-food sources that deliver bioavailable B vitamins in the form dogs are designed to use.

What Are B Vitamins and What Do They Do for Dogs?

The B vitamin complex includes eight distinct vitamins, each with specific roles in canine health:

B1 (Thiamine)

• Function: Converts carbohydrates into energy (ATP production)
• Supports: Nervous system function, muscle coordination, heart health
• Deficiency signs: Weakness, loss of appetite, neurological symptoms, heart problems

B2 (Riboflavin)

• Function: Energy metabolism, antioxidant activity, red blood cell production
• Supports: Skin and coat health, eye health, cellular energy
• Deficiency signs: Skin lesions, eye problems, poor growth

B3 (Niacin)

• Function: Energy production, DNA repair, hormone synthesis
• Supports: Digestive health, skin health, brain function
• Deficiency signs: GI issues, skin lesions (pellagra-like symptoms), neurological problems
• Important: Dogs can't convert tryptophan to niacin efficiently like humans, so they need dietary niacin

B5 (Pantothenic Acid)

• Function: Synthesizes coenzyme A (essential for metabolism), hormone production
• Supports: Energy production, adrenal function, wound healing
• Deficiency signs: Lethargy, GI issues, poor growth

B6 (Pyridoxine)

• Function: Amino acid metabolism, neurotransmitter synthesis, red blood cell formation
• Supports: Brain health, immune function, protein utilization
• Deficiency signs: Anemia, skin lesions, seizures, poor growth

B7 (Biotin)

• Function: Fat and carbohydrate metabolism, skin and coat health
• Supports: Healthy skin, shiny coat, nail strength
• Deficiency signs: Hair loss, dry/flaky skin, brittle nails
• Note: Dogs produce some biotin in the gut, but dietary sources are still important

B9 (Folate/Folic Acid)

• Function: DNA synthesis, cell division, red blood cell formation
• Supports: Growth, reproduction, immune function
• Deficiency signs: Anemia, poor growth, immune dysfunction
• Important distinction: Folate (from food) is more bioavailable than synthetic folic acid

B12 (Cobalamin)

• Function: Red blood cell formation, DNA synthesis, nervous system function
• Supports: Energy production, brain health, GI function
• Deficiency signs: Anemia, weakness, neurological symptoms, GI issues
• Critical note: B12 is only found in animal-based foods — dogs on plant-based diets are at high risk of deficiency

Why Are B Vitamins Missing from Most Kibble?

B vitamins are naturally abundant in raw meat, organs, and fresh foods. So why are they deficient in most commercial dog foods?

1. High-Heat Processing Destroys B Vitamins

Most dry kibble is manufactured through a process called extrusion, where ingredients are cooked at 300-400°F under high pressure. Certain B vitamins—particularly thiamin (B1) and folic acid—are highly heat-sensitive and degrade significantly at these temperatures, with vitamin B1 and folic acid being among the most affected by extrusion processing. Other B vitamins like B2, B6, B12, niacin, and biotin are more stable during processing:

• Thiamine (B1): Up to 90% loss during extrusion
• Folate (B9): 50-80% loss
• B12 (Cobalamin): 30-60% loss
• B6 (Pyridoxine): 40-70% loss

Even foods that start with high-quality ingredients lose most of their naturally occurring B vitamins by the time processing is complete.

2. Synthetic B Vitamins Are Added Back — But They're Less Bioavailable

To meet AAFCO minimum requirements, most manufacturers spray synthetic B vitamins onto kibble after processing. However, synthetic B vitamins are isolated compounds that lack the co-factors found in whole foods.

For example:

• Folic acid (synthetic) vs folate (food-based): Folate from liver or leafy greens is absorbed 50-80% more efficiently than synthetic folic acid
• Synthetic B12 vs food-based B12: Food-based B12 comes with intrinsic factor and other co-factors that support absorption
• Isolated B vitamins: Don't provide the synergistic benefits of the full B-complex as found in organ meats

For more on why whole-food nutrients outperform synthetics, see Whole Food vs. Synthetic: Why Bioavailability Matters in Your Dog's Nutrition.

3. AAFCO Minimums Don't Reflect Optimal Health

AAFCO standards are designed to prevent deficiency diseases — not to optimize health or longevity. A dog can technically "meet requirements" while still being suboptimal in B vitamins, especially if they:

• Are highly active (increased energy demands = higher B vitamin needs)
• Are senior (reduced absorption efficiency)
• Have digestive issues (IBD, EPI, pancreatitis reduce B12 absorption)
• Are under stress (illness, surgery, environmental stressors increase B vitamin utilization)

Signs of B Vitamin Deficiency in Dogs

Because B vitamins aren't stored long-term, deficiency symptoms can appear relatively quickly when intake is inadequate. Common signs include:

• Lethargy and low energy — Reduced ATP production affects stamina and vitality
• Poor appetite or weight loss — B vitamins are essential for metabolism
• Dull coat or skin issues — Particularly biotin and riboflavin deficiency
• Weakness or muscle wasting — Impaired protein metabolism
• Neurological symptoms — Tremors, seizures, loss of coordination (especially B1 and B12 deficiency)
• Anemia — Pale gums, weakness, exercise intolerance (B12, folate, B6 deficiency)
• GI issues — Diarrhea, vomiting, poor digestion

B12 deficiency is particularly common in dogs with:

• Inflammatory bowel disease (IBD)
• Exocrine pancreatic insufficiency (EPI)
• Chronic pancreatitis
• Small intestinal bacterial overgrowth (SIBO)

These conditions impair B12 absorption in the gut, leading to deficiency even when dietary intake appears adequate.

Best Whole-Food Sources of B Vitamins for Dogs

The most bioavailable sources of B vitamins for dogs come from animal-based whole foods — particularly organ meats.

1. Beef Liver (Richest Source of Nearly All B Vitamins)

Beef liver is the single most concentrated source of B vitamins available. Just 1 ounce provides:

• B12 (Cobalamin): 30-40 mcg (3000%+ of daily needs for a 50 lb dog)
• Folate: 80-100 mcg
• Riboflavin (B2): 1.0-1.2 mg
• Niacin (B3): 5-6 mg
• B6 (Pyridoxine): 0.4-0.5 mg
• Pantothenic acid (B5): 2-3 mg
• Biotin (B7): 25-30 mcg

No other single food comes close to liver's B vitamin density. And because these vitamins come from whole food, they're packaged with co-factors (iron, selenium, amino acids, vitamin A) that enhance absorption and utilization.

For more on liver's nutrient density, see Why Beef Liver is One of the Best Things You Can Feed Your Dog.

2. Beef Kidney

Kidney is another excellent source of B vitamins, particularly B12, riboflavin, and folate. It also provides selenium and other trace minerals that support B vitamin function.

3. Beef Heart

Heart is rich in B vitamins (especially B12, B6, and niacin) plus CoQ10 and taurine — nutrients that support energy production and cardiovascular health.

4. Eggs (Especially Yolks)

Egg yolks provide biotin, B12, folate, and riboflavin. They're also rich in choline, which works synergistically with B vitamins to support brain and liver function.

5. Wild-Caught Salmon

Salmon provides B12, niacin, B6, and riboflavin, plus omega-3 fatty acids that support brain health and reduce inflammation.

6. Nutritional Yeast (For Plant-Based Diets — Use with Caution)

Nutritional yeast is often fortified with B vitamins and can provide B12 for dogs on plant-based diets. However, dogs absorb animal-based B vitamins far more efficiently than plant-based or fortified sources. If feeding a plant-based diet, B12 supplementation (ideally from animal sources) is critical.

How Much B Vitamins Do Dogs Need?

B vitamin requirements vary by size, age, and activity level. AAFCO provides minimum guidelines, but optimal levels are often higher — especially for active, senior, or stressed dogs.

As a general guideline for a 50 lb adult dog:

• B12: ~1-2 mcg/day (minimum), but higher amounts (5-10 mcg) support energy and brain function
• Folate: ~25-50 mcg/day
• B6: ~0.5-1 mg/day
• Niacin: ~5-10 mg/day
• Riboflavin: ~1-2 mg/day
• Thiamine: ~0.5-1 mg/day

Feeding just 1-2 oz of beef liver per day provides 100-300%+ of these needs — making it the most efficient way to ensure adequate B vitamin intake.

Whole-Food B Vitamins vs Synthetic B Vitamins

Not all B vitamins are absorbed equally. Here's how whole-food sources compare to synthetic supplements:

Synthetic B Vitamins (Cyanocobalamin, Folic Acid, Pyridoxine HCl)

• Absorption: 30-50% bioavailability (isolated compounds without co-factors)
• Form: Often inactive forms that require conversion (e.g., folic acid → folate, cyanocobalamin → methylcobalamin)
• Co-factors: None — the body has to process them without supporting nutrients
• Synergy: Limited — isolated B vitamins don't work as effectively as the full complex

Whole-Food B Vitamins (Organ Meats, Eggs, Fish)

• Absorption: 60-80% bioavailability (co-factors support uptake)
• Form: Already in active, bioavailable forms (methylcobalamin, methylfolate, etc.)
• Co-factors: Packaged with amino acids, minerals, and other vitamins that enhance utilization
• Synergy: Full B-complex works together as nature intended

This is why Watts uses beef liver, beef kidney, and beef heart — to deliver B vitamins in the form dogs' bodies are designed to use, not synthetic isolates.

Why Watts Uses Whole-Food B Vitamins

At Watts, we prioritize organ meats (beef liver, beef kidney, beef heart) because they're the richest, most bioavailable sources of B vitamins available.

Each serving provides:

• 3000%+ of daily B12 needs from beef liver — supporting energy, brain function, and red blood cell formation
• High levels of folate, riboflavin, niacin, B6, and pantothenic acid — the full B-complex as nature packages it
• Co-factors like iron, selenium, and amino acids — enhancing absorption and utilization

We don't use synthetic B vitamins (cyanocobalamin, folic acid, pyridoxine HCl) because:

• Lower absorption: Synthetic forms are absorbed at 30-50% efficiency vs 60-80%+ for whole-food sources
• Inactive forms: Require conversion in the body, which not all dogs do efficiently
• No synergy: Isolated B vitamins don't work as well as the full complex found in organ meats

By using whole-food sources, Watts delivers B vitamins the way dogs have evolved to absorb them — efficiently, naturally, and without the limitations of synthetic supplements.

For more on organ-based nutrition, see The Real Benefits of Organ-Based Nutrition for Dogs.

Final Thoughts

B vitamins are essential for energy production, brain function, metabolism, and overall vitality in dogs. Yet most commercial dog foods are deficient in B vitamins due to high-heat processing, and the synthetic B vitamins added back are far less bioavailable than naturally occurring forms.

The best way to ensure your dog gets adequate B vitamins is through whole-food sources — particularly beef liver, which delivers the full B-complex in its most bioavailable form. Even small amounts (1-2 oz daily) can make a significant difference in energy, coat quality, and long-term health.

If you want a simple, pre-portioned way to give your dog whole-food B vitamins every day, that's exactly what Watts is designed to do.