Vitamin B3 (Niacin)
Last updated: August 9, 2026
Benefits
Central to how every cell releases energy from food, and supports normal skin and nervous-system function.
How much you need
Recommended daily amounts by life stage, per NIH and NASEM Dietary Reference Intakes. Where the evidence hasn't been enough to set a full RDA (Recommended Dietary Allowance), NASEM sets an AI (Adequate Intake) instead — both are shown together below.
| Life stage | RDA / AI |
|---|---|
| Children 1–3 | 6 mg |
| Children 4–8 | 8 mg |
| Boys 9–13 | 12 mg |
| Girls 9–13 | 12 mg |
| Males 14–18 | 16 mg |
| Females 14–18 | 14 mg |
| Men 19–50 | 16 mg |
| Women 19–50 | 14 mg |
| Men 51–70 | 16 mg |
| Women 51–70 | 14 mg |
| Men 71+ | 16 mg |
| Women 71+ | 14 mg |
| Pregnancy 14–18 | 18 mg |
| Pregnancy 19–50 | 18 mg |
| Lactation 14–18 | 17 mg |
| Lactation 19–50 | 17 mg |
Upper limit
This limit counts supplemental niacin from supplements only — the amount you get from food does not count toward it.
| Life stage | Tolerable upper limit |
|---|---|
| Children 1–3 | 10 mg |
| Children 4–8 | 15 mg |
| Boys 9–13 | 20 mg |
| Girls 9–13 | 20 mg |
| Males 14–18 | 30 mg |
| Females 14–18 | 30 mg |
| Men 19–50 | 35 mg |
| Women 19–50 | 35 mg |
| Men 51–70 | 35 mg |
| Women 51–70 | 35 mg |
| Men 71+ | 35 mg |
| Women 71+ | 35 mg |
| Pregnancy 14–18 | 30 mg |
| Pregnancy 19–50 | 35 mg |
| Lactation 14–18 | 30 mg |
| Lactation 19–50 | 35 mg |
High supplemental niacin can cause skin flushing, itching, and nausea — flushing is the effect this limit is set by, and it comes from nicotinic acid rather than niacinamide. Liver problems appear only at gram-scale doses, roughly a hundred times this limit, generally taken under medical supervision. The official limit also counts niacin added to enriched grains and fortified cereals; the figure here counts supplements only.
Best food sources
| Serving | ||
|---|---|---|
| Chicken and turkey | — | — |
| Tuna and salmon | — | — |
| Peanuts | — | — |
| Brown rice | — | — |
| Fortified cereals | — | — |
Body systems & goals
Goals it supports
- Energy & stamina (emerging evidence)
Frequently asked questions
How much Vitamin B3 (Niacin) do adult women need per day?
Adult women (19–50) need 14 mg of Vitamin B3 (Niacin) per day, per NIH/NASEM Dietary Reference Intakes.
How much Vitamin B3 (Niacin) do adult men need per day?
Adult men (19–50) need 16 mg of Vitamin B3 (Niacin) per day, per NIH/NASEM Dietary Reference Intakes.
Does pregnancy change how much Vitamin B3 (Niacin) you need?
Yes — during pregnancy (ages 19–50) the recommended amount rises to 18 mg per day, compared with 14 mg for non-pregnant adult women.
Is there an upper limit for Vitamin B3 (Niacin)?
Yes — for adults 19–50, the tolerable upper limit is 35 mg (measured as supplemental niacin). High supplemental niacin can cause skin flushing, itching, and nausea — flushing is the effect this limit is set by, and it comes from nicotinic acid rather than niacinamide. Liver problems appear only at gram-scale doses, roughly a hundred times this limit, generally taken under medical supervision. The official limit also counts niacin added to enriched grains and fortified cereals; the figure here counts supplements only.
What foods are highest in Vitamin B3 (Niacin)?
Good sources include Chicken and turkey, Tuna and salmon, Peanuts, Brown rice, and Fortified cereals.
How Tavita handles this
Tavita logs Vitamin B3 (Niacin) from both the food you eat and the supplements you take, adding both into one running daily total. It warns you before you reach the tolerable upper limit, counting only what comes from supplements, since that's what this particular limit is defined against.
Sources
Figures on this page come from the NIH Office of Dietary Supplements fact sheets and the National Academies of Sciences, Engineering, and Medicine (NASEM) Dietary Reference Intake tables — the same dataset that powers the Tavita app. They were independently re-verified by blind re-derivation on August 9, 2026. See the methodology page for how this library is built and kept current.
Tavita is not a medical provider. This page is educational information, not medical advice — talk to your clinician before changing your supplement or medication routine.