Vitamin B complex
Also known as: Anivit 4BC · Dupharal · Duphafral Extravite · B-complex vitamins · Multivitamin B
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Vitamin B deficiency | 1 ml/dog (dogs up to 15 kg); 2-4 ml/dog (dogs >15 kg) | SC/IM/IV | q24h | — | 🌍 EU |
- Vitamin B deficiency: Give IV slowly or diluted in fluids to prevent anaphylaxis.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Vitamin B deficiency | 1 ml/cat | SC/IM/IV | q24h or as required | — | 🌍 EU |
- Vitamin B deficiency: Give IV slowly or diluted in fluids to prevent anaphylaxis.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Vitamin B complex is a combination of water-soluble vitamins essential for various metabolic processes. It is primarily used to treat or prevent multiple deficiencies of B vitamins, which frequently occur in patients with renal disease, hepatic disease, or significant anorexia.
Clinical Warning: Parenteral administration of B vitamins is not a substitute for comprehensive nutritional support (e.g., enteral feeding).
Clinical Pearl: Many commercial injectable products are formulated for large animals and may contain additional vitamins (like Vitamin C) or minerals. Care must be taken to ensure the specific product is safe for small animals.
Mechanism of action
B vitamins act as essential cofactors for enzymes involved in intermediary metabolism and biosynthesis. They facilitate energy production, amino acid metabolism, and cellular maintenance.
Key pathways include:
- Thiamine (B1) → Carbohydrate metabolism
- Riboflavin (B2) & Niacin (B3) → Oxidation-reduction reactions (ATP production)
- Pyridoxine (B6) → Amino acid metabolism
- Cobalamin (B12) → Nucleic acid synthesis and red blood cell formation
Safety & warnings
Contraindications
- Known hypersensitivity to any component of the preparation
Adverse effects
- Anaphylaxis (particularly with rapid IV administration)
- Pain at injection site (IM/SC)
Precautions
Anaphylaxis Risk: Anaphylaxis may be seen when used intravenously. Products should be given slowly and/or diluted with IV fluids.
Toxicity Risk: Use of large animal products which also contain fat-soluble vitamins (A, D, E, K) may lead to toxicity in small animals. Always verify the exact composition of the multivitamin preparation.
- All B vitamins are photosensitive and must be protected from light once reconstituted.
- Multidose vials require strict aseptic technique for repeated use.
Monitoring
- Clinical signs of resolution of deficiency (improved appetite, energy)
- Monitor for signs of anaphylaxis during and immediately after IV administration
Pharmacokinetics
Absorption
Well absorbed from the gastrointestinal tract (PO) and injection sites (IM, SC).
Distribution
Widely distributed to all tissues.
Metabolism
Hepatic metabolism for some components; generally utilized directly by cells as cofactors.
Elimination
Excess water-soluble vitamins are rapidly excreted unchanged in the urine.
Overdose
Water-soluble B vitamins have a wide margin of safety, as excess is readily excreted in the urine. However, toxicity may occur if using large animal multivitamin products that also contain fat-soluble vitamins (A, D, E, K).
Available products
Formulations
- Injectable solution
- Tablets
Veterinary
- Anivit 4BC injection
- Dupharal injection
- Duphafral Extravite injection
- Multivitamin injection
- Vitamin B tablets
Human-labeled
- Various Vitamin B complex tablets and injections
Regulatory status
Many injectable preparations are authorized for farm animals only, requiring cascade/off-label use in companion animals.
Most parenteral forms are POM-VPS. Authorized for farm animals only; used off-label in dogs and cats.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Photosensitive; must be protected from light once reconstituted. Store according to manufacturer instructions. Multidose vials require aseptic technique for repeated use.
Client information
Vitamin B complex helps replenish essential nutrients in pets that are sick, have kidney or liver disease, or have not been eating well.
- Not a food substitute: This medication does not replace the need for your pet to eat a proper diet.
- Storage: If you are giving this medication at home, keep it protected from light.
- Urine color: You may notice your pet's urine turns a bright yellow color; this is normal and harmless.
- Allergic reactions: Contact your veterinarian immediately if you notice facial swelling, hives, or difficulty breathing after administration.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.