Is intramuscular (IM) biotin effective and what is the recommended dosing for treating biotin deficiency?

Intramuscular Biotin: Effectiveness and Dosing

The available guidelines do not support or provide specific recommendations for intramuscular (IM) biotin administration—oral biotin is the preferred route for rapid replenishment, even in severe deficiency, with IV biotin reserved only for parenteral nutrition-dependent patients who cannot receive enteral therapy. 1

Route of Administration Hierarchy

The 2022 ESPEN Micronutrient Guidelines establish a clear treatment algorithm based on intestinal function: 1

• First-line: Oral biotin is recommended for rapid replenishment in biotin deficiency
• Malabsorption/short bowel cases: Increase oral doses to 10 mg/day to overcome absorption defects 1
• IV biotin: Reserved exclusively for parenteral nutrition (PN)-dependent patients requiring up to 200 mg/day for 2-3 weeks 1
• Route flexibility: Additional biotin can be administered orally, enterally, or IV depending on intestinal function 1

Critical Gap: No IM Biotin Data

Notably absent from all biotin guidelines is any mention of intramuscular administration. 1 This contrasts sharply with other micronutrients where IM routes are explicitly discussed—for example, the 2023 bariatric surgery vitamin D guidelines found that high-dose IM vitamin D supplementation resulted in higher serum levels and lower deficiency rates compared to oral supplementation in malabsorptive surgery patients. 1

The ESPEN guidelines' recommendation that "additional amounts of biotin can be administered either orally, enterally or IV depending on the intestinal function" 1 conspicuously omits IM as an option, suggesting this route lacks evidence or clinical precedent.

Oral Biotin Effectiveness

Oral biotin demonstrates rapid clinical response even in severe deficiency states: 2, 3

• A 2-month-old with biotinidase deficiency showed dramatic improvement in seizures within 48 hours of oral biotin 10 mg twice daily, with complete resolution of skin/hair lesions 2
• A 5-month-old with biotin deficiency on amino acid formula achieved complete resolution of periorificial dermatitis and organic aciduria with only 1 mg/day oral biotin 3
• Biotin absorption is nearly complete in humans under normal circumstances 4

Dosing Recommendations (Oral/Enteral/IV Only)

Standard maintenance (enteral nutrition): At least 30 mcg/day in 1500 kcal (Grade B recommendation) 1

Parenteral nutrition: 60 mcg/day (Grade B recommendation) 1

Treatment of deficiency: 1

• Oral: 10 mg/day for malabsorption/short bowel
• IV (PN-dependent only): Up to 200 mg/day for 2-3 weeks

Special populations: 1

• Pregnancy: May require up to 300 mcg/day based on metabolic markers
• Breastfeeding: At least 35 mcg/day orally
• Renal replacement therapy: Additional amounts may be needed

Clinical Pitfalls

Biotin depletion occurs rapidly in biotinidase deficiency—within 12 days in newborns and 15-20 days after withdrawal in established patients, primarily due to urinary losses of biotin and biocytin. 5 This underscores the need for immediate treatment when deficiency is suspected, but oral administration remains effective even in these urgent scenarios. 2

Safety profile: No upper limit established; no adverse effects reported with oral or IV doses up to 5 mg/day for prolonged periods. 1

Practical Algorithm

1. Suspect biotin deficiency based on dermatitis, alopecia, or neurological symptoms with inadequate intake history 1
2. Initiate oral biotin immediately (10 mg/day) while awaiting confirmatory testing 1
3. If oral route impossible (severe vomiting, dysphagia, PN-dependent): Use IV biotin up to 200 mg/day 1, 6
4. Never delay treatment for laboratory confirmation in symptomatic patients 2

In summary, IM biotin lacks guideline support and published evidence, making it an unvalidated route when oral and IV options are well-established and effective. 1