Niacin Intake Calculator
Score daily vitamin B3 percent and gap from foods by stage.
What it does
Niacin supports energy and skin from protein rich foods. Poultry, tuna, and peanuts carry it in amounts that cover most omnivore days.
The tool above scores the day. An adult woman target is 14 mg, so 12 mg reads 85.7 % with 2 mg more to find. Men target 16 mg, pregnancy 18 mg.
Poultry sets the pace. A single chicken breast with rice lands most of the day, while tuna sandwiches and peanut snacks finish it.
Protein helps twice. Meat and dairy supply tryptophan the body turns into niacin, so balanced protein rarely leaves gaps.
Weeks beat days. Fast food weekends and skipped lunches swing any single tally, so average seven before acting.
How to use
- Pick life stage.
- Enter food niacin in mg.
- Read target first.
- Read percent next.
- Read gap and add poultry or peanuts.
- Score a week, not one meal.
Formula
- stage
- Life stage setting the target.
- food
- Niacin from foods, in mg.
Targets are niacin equivalents following NIH ODS intakes. Food mg comes from labels or USDA FoodData entries summed for the day.
Worked example
Example: adult woman, 12 mg from food
Defaults: adult woman eating 12 mg. These are also the default values, so the page opens on this answer.
- Stage: adult woman, target 14 mg.
- Food: 12 mg from poultry and grains.
- Share: 12 / 14 x 100 = 85.7 %.
- Gap: 14 - 12 = 2 mg more.
- Tool shows 14 mg, 85.7 %, 2 mg more.
Reference table
| Stage | Target | Example score |
|---|---|---|
| Child | 8 mg | 6 mg is 75 % |
| Adult woman | 14 mg | 12 mg is 85.7 % |
| Adult man | 16 mg | 14 mg is 87.5 % |
| Pregnancy | 18 mg | 15 mg is 83.3 % |
Limits
- Intake scoring only, not medical advice.
- Labels vary by brand.
- Tryptophan conversion ignored in tally.
- Symptoms need clinicians, not math.
Common mistakes
- Scoring one meal instead of the day.
- Skipping protein, then wondering at gaps.
- Megadosing supplements for energy.
- Mixing mg with grams on labels.
- Treating percent as a diagnosis.
Try it yourself
Quick checks. Answers sit tucked under each question.
Adult man eating 14 mg?
Target is 16 mg. Share is 14 / 16 x 100 = 87.5 %. Gap is 2 mg more.
Pregnancy, eating 15 mg?
Target is 18 mg. Share is 15 / 18 x 100 = 83.3 %. Gap is 3 mg more.
Questions
How do I score my day?
Divide food mg by the stage target. Here 12 / 14 x 100 = 85.7 %.
What are the targets?
Kids 8 mg, teen girls and women 14 mg, teen boys and men 16 mg, pregnancy 18 mg, breastfeeding 17 mg.
Which foods carry niacin?
Poultry, tuna, peanuts, and fortified grains. A chicken breast with rice covers most of the day.
How do I close the gap?
Add poultry, tuna, or peanuts. Here 2 mg more closes the day.
Does protein help?
Yes. Protein foods carry tryptophan the body converts, so meat eaters rarely run short.
Does this diagnose deficiency?
No. Intake scoring only; skin and digestion signs need clinicians.