Is 500 mg of niacin too much?
500 milligrams of niacin (vitamin B3) is above the adult upper limit of 35 milligrams a day from supplements and fortified foods. Adults need 16 milligrams for men and 14 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.
In the UK
500 milligrams of niacin (vitamin B3) is above the NHS guidance of 17 milligrams a day of nicotinic acid from supplements. In the UK, adults need 16.5 milligrams a day for men and 13.2 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
The figures
| US (NIH) | UK (NHS) | |
|---|---|---|
| Amount checked | 500 mg (500 mg NE) | |
| Answer | Above the upper limit | Above NHS guidance |
| Compared with | 35 milligrams a day from supplements and fortified foods | 17 milligrams a day of nicotinic acid from supplements |
| Share of the limit | 1429% of the limit | 2941% of the limit |
| Adults need | 16 milligrams for men and 14 milligrams for women | 16.5 milligrams a day for men and 13.2 milligrams for women |
Good to know
- Above the upper limit, niacin often causes flushing: red, warm, itchy skin. Prescription doses are much higher and are taken only under a doctor.
Quick answers
- Is 500 mg of niacin too much?
- 500 milligrams of niacin (vitamin B3) is above the adult upper limit of 35 milligrams a day from supplements and fortified foods. Adults need 16 milligrams for men and 14 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
- What does the NHS say about 500 mg of niacin (vitamin B3)?
- 500 milligrams of niacin (vitamin B3) is above the NHS guidance of 17 milligrams a day of nicotinic acid from supplements. In the UK, adults need 16.5 milligrams a day for men and 13.2 milligrams for women. Doctors sometimes advise more for a set time, so check with yours before taking this much.
- What is the upper limit for niacin (vitamin B3)?
- US: 35 milligrams a day from supplements and fortified foods. UK (NHS): 17 milligrams a day of nicotinic acid from supplements.
Sources
- NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/ - NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/
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