What are the recommended uses and dosages of Nicotinamide (Vitamin B3) in medical treatment?

Recommended Uses and Dosages of Nicotinamide (Vitamin B3) in Medical Treatment

Nicotinamide (niacinamide) is primarily recommended at doses of 500 mg twice daily for prevention of keratinocyte carcinomas in high-risk patients and at doses of 100 mg three times daily for 3 weeks for treatment of pellagra. 1, 2, 3

Approved Medical Uses and Dosages

Dermatological Conditions

• Pemphigus Vulgaris and Bullous Pemphigoid

  • Recommended as an adjuvant therapy in combination with tetracyclines 2
  • Can be considered for milder cases of pemphigus vulgaris 2
  • Advantages: Inexpensive with fewer side effects compared to immunosuppressants 2

• Skin Cancer Prevention

  • Dosage: 500 mg twice daily 3
  • Particularly effective for solid organ transplant recipients at high risk for keratinocyte carcinomas
  • Demonstrated significant reduction in squamous cell carcinoma (SCC) and SCC in situ over one-year and two-year intervals 3

• Acne, Rosacea, and Aging Skin

  • Topical application shows benefit for these conditions 4
  • Mechanism: Anti-inflammatory effects via inhibition of leukocyte chemotaxis and bacteriostatic effect against Propionibacterium acnes 5

Nutritional Deficiency (Pellagra)

• Treatment Dosage: 100 mg three times daily for 3 weeks (total daily dose should not exceed 600 mg) 2
• Prevention Dosage: 1-2 tablets daily as a dietary supplement 6
• Populations at Risk: Maize-eating populations with limited dietary diversity 2
• Symptoms of Deficiency: Dermatitis, diarrhea, dementia, and potentially death if untreated 1

Daily Recommended Intake

• Men (over 14 years): 16 mg/day
• Women (over 14 years): 14 mg/day
• Pregnant women: 18 mg/day
• Lactating women: 16 mg/day 1

Upper Limits and Safety

• Nicotinamide: Approximately 900 mg/day for adults (12.5 mg/kg body weight/day) 1
• Nicotinic Acid (niacin): 10 mg/day due to risk of flushing reactions 1
• Important distinction: Nicotinamide does not cause the flushing reaction associated with nicotinic acid (niacin) 7

Administration and Formulations

• Oral Administration: Available as tablets (typically 250 mg) 6
• Storage: Store at 20° - 25°C (68° - 77°F) 6

Mechanism of Action

• Precursor of essential coenzymes for ATP production 8
• Regulates poly-ADP-ribose-polymerase 1, important for DNA repair 4
• Anti-inflammatory effects through inhibition of:
  • Leukocyte chemotaxis
  • Lysosomal enzyme release
  • Mast cell degranulation 5
• Protection against UV-induced skin damage 3

Monitoring and Precautions

• No specific laboratory monitoring required for standard supplementation
• For pellagra treatment, clinical improvement should be observed within weeks
• Excessive exposure may potentially contribute to diabetes, Parkinson's disease, and liver damage, though evidence is limited 8

Clinical Decision Algorithm

1. For Pellagra (Niacin Deficiency):

   • Confirm diagnosis through clinical symptoms (dermatitis, diarrhea, dementia)
   • Administer 100 mg three times daily for 3 weeks (not exceeding 600 mg/day) 2
   • Consider vitamin B complex if diet is generally deficient in niacin

2. For Skin Cancer Prevention in High-Risk Patients:

   • Particularly solid organ transplant recipients
   • Prescribe 500 mg twice daily 3
   • Continue long-term for sustained benefit

3. For Pemphigoid/Pemphigus:

   • Consider as adjuvant with tetracyclines for milder cases
   • Monitor for clinical improvement within 1-3 weeks 2

Nicotinamide represents a low-cost, generally safe therapeutic option with multiple dermatological applications and essential nutritional benefits when used at appropriate dosages.