Nutrient Guide
Vitamins for Dogs: A, D, E, K, B-Complex
Essential vitamins for dogs: learn about types, benefits, and risks of A, D, E, K, and B-complex vitamins for your dog's health and well-being.
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Vitamins for Dogs
Two Groups
Fat-Soluble (A, D, E, K): Stored in the liver; overdose can be dangerous.
Water-Soluble (B-Complex, C): Not stored (except B12); needed daily.
Vitamin A (Retinol)
- Function: Vision, immune system, cell differentiation, coat quality
- Source: Liver, fish oil, egg yolk
- Deficiency: Poor night vision, skin problems
- Overdose: Bone pain, liver problems. Never give human Vitamin A supplements.
Vitamin D
- Function: Calcium and phosphorus balance, bone health
- Source: Fish oil, liver, eggs. Dog skin does NOT produce Vitamin D from UV light.
- Deficiency: Rickets, osteoporosis
- Overdose: Dangerous (calcification, kidney damage), potentially fatal
Vitamin E
- Function: Antioxidant, cell membrane protection
- Source: Vegetable oils, liver, egg yolk
- Deficiency: Muscle weakness, neurological problems (rare)
Vitamin K
- Function: Blood clotting
- Source: Green leafy vegetables; also produced by gut bacteria
- Deficiency: Rare, except in cases of anticoagulant poisoning
B Vitamins
| Vitamin | Function | Deficiency |
|---|---|---|
| B1 (Thiamine) | Nervous system | Seizures |
| B2 (Riboflavin) | Energy production | Skin, eye problems |
| B3 (Niacin) | Metabolism | "Pellagra" |
| B5 (Pantothenic Acid) | Metabolism | Growth impairment |
| B6 (Pyridoxine) | Amino acid metabolism | Anemia |
| B7 (Biotin) | Coat, nails | Dermatitis |
| B9 (Folate) | Cell division | Anemia |
| B12 (Cobalamin) | Nervous system | Anemia, neurological issues |
Special Considerations for B12
- Found only in animal-derived sources
- Malabsorption in cases of IBD, EPI
- Injectable supplementation for chronic intestinal disease
- Essential for vegan dog diets
Vitamin C
Dogs produce their own Vitamin C. Supplementation may be beneficial during stress or illness.
When Are Supplements Needed?
Generally not, if fed a complete and balanced diet. Justified: confirmed deficiency, BARF/home-cooked diets, senior dogs, chronic illness.
Dangers of Overdosing
- Vitamin A: Bone pain, liver damage
- Vitamin D: Calcification, kidney damage (fatal!)
- B-Complex: Generally well-tolerated
Never give human multivitamins to dogs.
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References
- 1.National Research Council (US), Committee on Animal Nutrition — Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006. https://doi.org/10.17226/10668 (accessed: 2026-09-10)
- 2.FEDIAF (European Pet Food Industry Federation) — Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs. FEDIAF, 2024. https://europeanpetfood.org/self-regulation/nutritional-guidelines/ (accessed: 2026-09-10)
- 3.Association of American Feed Control Officials (AAFCO) — AAFCO Dog and Cat Food Nutrient Profiles. AAFCO Official Publication, 2024. https://www.aafco.org/consumers/understanding-pet-food/ (accessed: 2026-09-10)
- 4.Stockman J, Fascetti AJ, Kass PH, Larsen JA — Evaluation of recipes of home-prepared maintenance diets for dogs. Journal of the American Veterinary Medical Association 242(11):1500–1505, 2013. https://doi.org/10.2460/javma.242.11.1500 (accessed: 2026-09-10)
This is general information and does not replace a veterinary diagnosis.
This guide was compiled based on the expert input of Reka Fazekas-Birizdo canine nutritionist.
Certified Canine Nutritionist