Vitamin B3
Niacin (nicotinic acid), nicotinamide and nicotinamide riboside
A B vitamin found in meat, fish, eggs and wheat flour, also called niacin, nicotinic acid, nicotinamide and niacinamide. This page covers only studies in people that measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life. It is not all the research on vitamin B3. Here is every such study we could find, sorted from each study's summary.
- Found in: meat, fish, eggs, wheat flour
- Doses differ by form, in mg a day
- Often studied in people with a health condition
From every paper to the studies that matter
Most research on vitamin B3 is about diet, blood fats, skin, the lab or rare conditions. Only a small share gives it to people and measures thinking, memory, mood, stress, sleep, energy, tiredness or quality of life, and that is what this page is about.
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4,107 papers mention vitamin B3.Every record in PubMed, all years
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214 are about people.The rest: 1,740 lab and animal studies, 643 reviews, 1,510 on chemistry, farming and more
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20 give vitamin B3 on its own and measure these topics.73 more give it in a blend, such as with other B vitamins or minerals
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12 are randomised against a placebo.Randomised controlled trials In a randomised controlled trial, people are put into groups by chance, one taking the treatment and one a placebo or other comparison. Chance spreads differences such as age and health evenly, so a difference between the groups is more likely to be down to the treatment., the strongest kind of study
Bar lengths use a square-root scale so the small numbers stay visible.
How much research there is
- 20 studies giving vitamin B3 to people and measuring these topics
- 12 of them randomised against a placebo A placebo-controlled trial compares a real treatment with a dummy that looks the same, the placebo. People often feel better when they expect to, so comparing against a placebo shows how much of the change comes from the treatment itself.
- 3,032 people taking part, where studies say
- 62 systematic reviews A systematic review searches for every study on a question in a set, written-down way, judges the quality of each and sums up what they show together. Many include a meta-analysis. The Atlas lists these as pooled reviews. pooling the trials
Studies in people, by year published
Vitamin B3 on its own. Niacin added to a statin that the comparison group also took counts as on its own.
What the studies looked at
Each study can measure several things. Choose a topic to see its studies in the list below.
Studies in people with a diagnosed condition are counted here and listed with their population. We describe what they measured, not what they might treat. Most studies also report safety; see below.
What was tested, and how much
Vitamin B3 comes as different compounds, so milligrams do not compare neatly. Nicotinic acid, nicotinamide and nicotinamide riboside are different molecules, and some studies use extended-release tablets or injections. Doses range from 250 mg to 3,000 mg a day. The few doses far to the right are high doses used in trials, and some studies gave a single dose.
Daily amount, one dot per study
Studies per extract
Named extracts are the maker's brand. "Not named" means the study didn't say.
All studies in people
Filter the list, then open a study on PubMed. Each row comes from the study's published summary. Many studies give vitamin B3 inside a blend or multivitamin, which this page counts but does not list.
| Study | Who took part | People | Extract and daily dose | Length |
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| DeBoer 2026RCT, placebo | Lactating mothers and infants, rural Tanzania | 1,173 | Nicotinamide, 250 mg | 26 weeks |
| Martens 2026RCT, placebo | Older adults with amnestic MCI | 42 | Nicotinamide riboside | 12 weeks |
| Wu 2025RCT, placebo | Adults with long-COVID | 58 | Nicotinamide riboside, 2,000 mg | 20 weeks |
| Grill 2025RCT, placebo | Adults with early Alzheimer's disease | 47 | Nicotinamide, 3,000 mg | 48 weeks |
| Ketron 2025RCT, placebo | Adults with early Alzheimer's disease | 47 | Nicotinamide, 3,000 mg | 52 weeks |
| Wu 2025Crossover, placebo | Older adults with subjective cognitive decline or MCI | 46 | Nicotinamide riboside, 1,000 mg | 8 weeks |
| Szarvas 2025Single-arm or open-label | Older adults with peripheral artery disease | 8 | Nicotinamide riboside | 4 weeks |
| Orr 2024RCT, placebo | Older adults with mild cognitive impairment | 20 | Nicotinamide riboside, 1,000 mg | 10 weeks |
| El-Kady 2022RCT, active or other control | Diabetic NAFLD patients | 70 | Nicotinamide, 1,000 mg | 12 weeks |
| Parpia 2021RCT, placebo | Tanzanian infants | 1,032 | Nicotinamide | – |
| Wakade 2021RCT, placebo | Parkinson's disease veterans | 47 | Niacin | 26 weeks |
| Chong 2021Single-arm or open-label | Adults with Parkinson's disease | – | Niacin | 52 weeks |
| Dolopikou 2020Crossover, placebo | Young and old men | 24 | Nicotinamide riboside | – |
| Martin 2019RCT, placebo | Adults with prior skin cancer | 310 | Nicotinamide, 1,000 mg | 52 weeks |
| Leckey 2016Crossover, placebo | Competitive runners | 12 | Nicotinic acid | – |
| Loriaux 1985Non-randomised controlled | Healthy young, middle-aged and old adults | 96 | Nicotinic acid, 425 mg | 8 weeks |
| Ban 1970Other | Patients with schizophrenia | – | Nicotinic acid | – |
| TONGE 1953Other | Patients with depression | – | Nicotinic acid | – |
| WASHBURNE 1950Single-arm or open-label | Patients with depressed states | – | Nicotinic acid | – |
| BUSCAINO 1948Other | Patients with early dementia | – | Nicotinic acid | – |
What's known about safety
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In trials
In a placebo-controlled trial of 3,000 mg a day of nicotinamide for 48 weeks in 47 people with early Alzheimer disease, side effects were balanced between the groups, with few linked to treatment. An 8-week crossover trial of 1,000 mg a day of nicotinamide riboside in 46 older adults found no difference in side effects between nicotinamide riboside and placebo.
Grill 2025, Neurology (PMID 39671543); Wu 2025, Alzheimer's & Dementia (PMID 39817194)
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In the UK
The NHS says the Department of Health and Social Care advises that 17 mg or less a day of nicotinic acid supplements, or 500 mg or less a day of nicotinamide supplements, is unlikely to cause harm. It says high doses of nicotinic acid can cause skin flushes. We did not confirm the UK status of nicotinamide riboside.
NHS vitamins and minerals, vitamin B pages (opened Oct 2026); searches of the FSA novel foods guidance did not name nicotinamide riboside
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Check first
The NHS says taking high doses of nicotinic acid for a long time could lead to liver damage, and that there isn't enough evidence on high daily doses of nicotinamide. We found no source on pregnancy, breastfeeding or medicines. Speak to a pharmacist or doctor first if you take medicines, have liver problems or are pregnant.
NHS vitamins and minerals, vitamin B pages (opened Oct 2026); no pregnancy or interaction guidance found
Where these studies come from
We list every published study giving vitamin B3 on its own to people that measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life. The count is not all research on the vitamin. It leaves out studies that only measure blood levels, diet or genes, studies where only the comparison group got the vitamin, and NMN. Niacin added to a statin the comparison group also took counts as on its own. Niacin given with laropiprant counts as in a blend. This first version is built from each study's summary; full-paper checks come next.
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We search
PubMed, the world's main library of medical research, for every paper on L-theanine.
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We keep studies in people
Lab and animal work is counted but left out of the list, because it doesn't tell you what happens in people.
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We note the basics
Who took part, how many, how much and for how long, from each study's published summary. A second check corrects what the first read gets wrong.
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We read them in full
Results appear once we've read the whole paper and checked every number. The date at the top shows when this entry was last updated.
Download the study list
Every study in people as a spreadsheet, 20 rows, free to reuse with a link back.
Versions
Each update to the data gets a new version number, so you can tell what changed and when.
See every version
1.0 · 24 Oct 2026. First release. Every published study giving vitamin B3 to people that measured thinking, memory, mood, stress, sleep, energy or quality of life is listed from its summary. None is read in full yet.
