Niacin Dosage Guide

Recommended daily intake by age and gender — based on NIH Dietary Reference Intakes.

Our assessment

Based on the provided data, niacin from food and beverages is safe, but dietary supplements containing 30 mg or more of nicotinic acid can cause specific adverse effects. At doses of 1,000 mg or more per day, the risk of more severe side effects increases FDA FAERS ↗.

How it works

Niacin is a B vitamin that the body uses to convert food into energy. When taken as a dietary supplement in doses of 30 mg or more of nicotinic acid, it can cause a reaction known as "niacin flush," which is not harmful but can be uncomfortable NIH ODS ↗.

Safety profile

Based on FDA data, side effects from nicotinic acid supplements include a red, burning, tingling, and itching sensation on the skin of the face, arms, and chest, along with headaches, rashes, and dizziness. At doses of 1,000 mg or more per day, more severe side effects can occur, including low blood pressure (increasing fall risk), extreme tiredness, and high blood sugar levels FDA FAERS ↗.

Our recommendation

Individuals taking tuberculosis drugs such as isoniazid and pyrazinamide should be cautious, as these medications can interfere with the body's ability to convert tryptophan to niacin. If you experience the niacin flush, it is a known side effect; however, if you are taking high doses (1,000 mg/day or more) and experience symptoms like low blood pressure, extreme tiredness, or high blood sugar, consult a healthcare provider immediately FDA FAERS ↗ NIH DSLD ↗.

AI-assisted analysis. Data sourced from NIH ODS.

Understanding RDAs

Dietary Reference Intakes (DRIs) are a set of reference values used to plan and assess nutrient intakes of healthy people. They include:

  • RDA (Recommended Dietary Allowance) — The average daily intake sufficient to meet the nutrient requirements of nearly all (97-98%) healthy individuals.
  • AI (Adequate Intake) — Established when evidence is insufficient to develop an RDA. Based on observed nutrient intake by healthy people.
  • UL (Tolerable Upper Intake Level) — The maximum daily intake unlikely to cause adverse health effects. Exceeding the UL increases the risk of toxicity.

Values vary by age, gender, and life stage (pregnancy, lactation).

Source: National Academies of Sciences, Engineering, and Medicine

Recommended Dietary Allowance

Niacin RDA / AI by Age and Gender
Life StageRecommended Amount
Birth to 6 months2 mg
Infants 7–12 months4 mg NE
Children 1–3 years6 mg NE
Children 4–8 years8 mg NE
Children 9–13 years12 mg NE
Teen boys 14–18 years16 mg NE
Teen girls 14–18 years14 mg NE
Adult men 19+ years16 mg NE
Adult women 19+ years14 mg NE
Pregnant teens and women18 mg NE
Breastfeeding teens and women17 mg NE

Source: National Academies of Sciences, Engineering, and Medicine