Vitamin B complex for dogs covers a group of water-soluble vitamins including thiamine (B1), riboflavin (B2), niacinamide (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B9), and cobalamin (B12), each with a distinct role in energy metabolism, nerve function, skin health, or cell division. Most complete commercial diets provide adequate levels of all of them, though B3, B6, and folic acid have more specific evidence behind targeted use for skin, mood, and gut health respectively.
The B complex isn't one vitamin. It's a group that happens to share a naming convention and often turns up together in the same foods. Dogs can't store most of them in any meaningful quantity, which means a shortfall in the diet shows up faster than it would with a fat-soluble vitamin like A or D. Here's what each one actually does.
Thiamine (B1)
Thiamine is involved in converting food into usable energy at the cellular level. A genuine deficiency is uncommon on a complete commercial diet but shows up as neurological symptoms when it happens, which is one reason it's included as a baseline safeguard in daily formulas rather than left to chance.
Riboflavin (B2)
Riboflavin supports the enzymes involved in energy production and also plays a role in maintaining healthy skin and coat. It's one of the more heat-sensitive vitamins, which is part of why processed foods are fortified with it rather than relying on naturally occurring levels alone.
Niacinamide (B3)
Niacinamide, the form of B3 used in supplements, supports cellular energy metabolism and skin barrier function. Research on the compound has focused heavily on skin: it's involved in pathways linked to epidermal renewal, barrier resilience, and hydration of the outermost skin layer (Boo, 2021; Sjöberg et al., 2025). That makes it a natural fit alongside a fibre blend rather than an energy formula, since gut and skin health tend to move together in dogs, as covered in our piece on digestive and skin signals. Broono Prebiotic includes niacinamide for this reason.
Pantothenic acid (B5)
Pantothenic acid is a building block for coenzyme A, a molecule involved in nearly every metabolic pathway in the body, from fat breakdown to hormone production. It's rarely deficient on its own but works alongside the other B vitamins rather than in isolation.
Pyridoxine (B6)
Pyridoxine is involved in amino acid metabolism and neurotransmitter synthesis. It's had more specific research attention recently in the context of stress and mood: human trials have found it enhances the effect of magnesium on markers of stress when the two are given together (Pouteau et al., 2018; Noah et al., 2021), and a 2022 study found high-dose B6 reduced anxiety measures directly (Field et al., 2022). Broono Calm includes it for this reason, alongside magnesium.
Folic acid (B9)
Folic acid supports DNA synthesis and cell division, which makes it particularly relevant to the gut lining, one of the fastest-renewing tissues in the body. A 2023 study found folate concentrations were associated with clinical signs and lab markers in dogs with chronic enteropathy, suggesting a more direct link between this vitamin and digestive health than is often assumed (Ullal et al., 2023).
Cobalamin (B12)
Cobalamin is essential for red blood cell formation and nerve function. Unlike the other B vitamins, it's stored in the liver in modest amounts, but dogs with digestive disease often can't absorb it properly regardless of dietary intake, which is why vets sometimes give it by injection rather than by mouth in sick dogs.
Where dogs get B vitamins
A complete, properly formulated diet should provide baseline levels of all of them. Meat, organ meat, and whole grains are naturally rich sources. Where a daily supplement adds value isn't in fixing a deficiency in a healthy dog eating a complete diet, it's in providing a measured, consistent top-up alongside the other ingredients in a formula, particularly B3 for skin, B6 for mood, and folic acid for gut health, the three with the most specific evidence behind targeted use.
Broono spreads the B complex across three products rather than one blanket formula: Essential includes thiamine, riboflavin, pantothenic acid, folic acid, and B12 for daily immune and energy support; Calm includes pyridoxine (B6) alongside magnesium; Prebiotic includes niacinamide (B3) alongside its fibre blend. Each is formulated against the research above rather than included as an undifferentiated "B complex" without individual justification.
References
- Boo, Y.C. (2021) 'Mechanistic basis and clinical evidence for the applications of nicotinamide (niacinamide) to control skin aging and pigmentation', Antioxidants, 10(8), 1315.
- Sjöberg, T., Fsahaye, A., Nilsson, E.J., Letasiova, S., Namro, I., Visdal-Johnsen, L., Hrapovic, N., Smiljanic, S., Österlund, C., Engblom, J. and Björklund, S. (2025) 'Niacinamide and its impact on stratum corneum hydration and structure', Scientific Reports, 15, 4953.
- Pouteau, E., Kabir-Ahmadi, M., Noah, L., Mazur, A., Dye, L., Hellhammer, J., Pickering, G. and Dubray, C. (2018) 'Superiority of magnesium and vitamin B6 over magnesium alone on severe stress in healthy adults with low magnesemia: a randomized, single-blind clinical trial', PLOS ONE, 13(12), e0208454.
- Noah, L., Dye, L., Bois De Fer, B., Mazur, A., Pickering, G. and Pouteau, E. (2021) 'Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: post-hoc analysis of a randomised controlled trial', Stress and Health, 37(5), pp. 1000-1009.
- Field, D.T., Cracknell, R.O., Eastwood, J.R., Scarfe, P., Williams, C.M., Zheng, Y. and Tavassoli, T. (2022) 'High-dose vitamin B6 supplementation reduces anxiety and strengthens visual surround suppression', Human Psychopharmacology: Clinical and Experimental, 37(6), e2852.
- Ullal, T.V., Marks, S.L., Huebner, S.N., Taylor, S.L. and Shelley, C.D. (2023) 'Association of folate concentrations with clinical signs and laboratory markers of chronic enteropathy in dogs', Journal of Veterinary Internal Medicine, 37(2), pp. 455-464.
