Know Your Blood Parameter : Vitamin B3 (Niacin)

1. Parameter Name 

Vitamin B3 (Niacin)

2. Test Type 

Blood (Serum Niacin or urinary metabolites; rarely tested directly unless deficiency is suspected)

3. Normal Range 

Typically assessed via urinary metabolites; reference range varies by testing method. No widely standardized serum reference range.

4. High Levels Indicate 

Can result from excessive supplementation and may lead to liver toxicity, skin flushing, increased blood sugar, and gastrointestinal issues.

5. Low Levels Indicate 

Deficiency may cause pellagra—a condition characterized by the "3 Ds": Dermatitis, Diarrhea, and Dementia, and eventually death if untreated.

6. Why It's Tested 

To assess for deficiency in malnourished individuals, those with chronic alcoholism, or patients with malabsorption syndromes. Also sometimes monitored in those taking high-dose niacin for cholesterol management.

7. Associated Symptoms (if abnormal)

• Low: Fatigue, depression, skin inflammation (especially in sun-exposed areas), diarrhea, memory problems

• High: Flushing, itching, liver enzyme elevation, nausea, glucose intolerance

  
  

8. What To Do If Abnormal

• Low: Improve dietary intake (e.g., meats, poultry, fish, nuts, whole grains), or use niacin supplements as prescribed.

• High: Reduce or discontinue supplements under medical guidance.

9. Common Conditions Related

• Pellagra (deficiency)

• Liver dysfunction (toxicity)

• Hartnup disease (a genetic cause of niacin deficiency)

10. Nutrition or Lifestyle Connection 

Niacin is found in animal proteins, peanuts, legumes, whole grains, fortified cereals. The body can also synthesize niacin from tryptophan (an amino acid found in protein).

11. References (APA Format)  National Institutes of Health. (2023). Vitamin B3 (Niacin) — Fact Sheet for Health Professionals. 

Whitney, E., & Rolfes, S. R. (2020). Understanding Nutrition (15th ed.). Cengage Learning. Pagana, K. D., & Pagana, T. J. (2021). Mosby’s Diagnostic and Laboratory Test Reference.