HealthMap

Tolerable Upper Intake Level (UL) for Niacin (Vitamin B3)

Based on data from the Food and Nutrition Board of the Institute of Medicine, the Tolerable Upper Intake Level (UL) for niacin depends on the specific form being consumed and the age group.

Nicotinic Acid Form (Flush-producing)

For adults, the UL for synthetic nicotinic acid (the form found in supplements and fortified foods that commonly causes flushing) is established to prevent adverse effects such as liver damage and vasodilation:

• Adults (19 years and older): 35 mg/day
• Pregnant and Lactating Women (19+ years): 35 mg/day
• Adolescents (14-18 years): 30 mg/day
• Children (9-13 years): 20 mg/day
• Children (4-8 years): 15 mg/day
• Children (1-3 years): 10 mg/day

Nicotinamide Form (Non-flushing)

• The ULs listed above specifically apply to nicotinic acid.
• The nicotinamide form (niacinamide) does not cause the characteristic flush, but high doses can still lead to other adverse health effects (such as liver toxicity). Therefore, caution is advised, and intake should not exceed sensible therapeutic limits without professional medical supervision.

Important Clinical Considerations

• Acu-Cell Nutrition perspective: The established ULs are designed to protect the general population from adverse pharmacological side effects. However, individual biochemical individuality, existing liver conditions, and specific health goals mean that optimal or therapeutic intakes can vary significantly under practitioner guidance.
• Prescription vs. Supplement: Much higher doses of nicotinic acid (often 1,500 mg to 3,000 mg/day or more) have been used medically under strict doctor supervision for lipid management, but these drastically exceed the safety threshold (UL) and carry a high risk of hepatotoxicity and other metabolic complications if self-administered.