Is 1000 mcg of B12 too much?
1,000 micrograms of vitamin B12 has no set upper limit. That is about 417 times the adult RDA of 2.4 micrograms.
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
1,000 micrograms of vitamin B12 is within the NHS guidance of 2 milligrams (2,000 micrograms) a day from supplements. In the UK, adults need 1.5 micrograms a day.
The figures
| US (NIH) | UK (NHS) | |
|---|---|---|
| Amount checked | 1,000 mcg | |
| Answer | No upper limit set | Within NHS guidance |
| Compared with | No upper limit has been set for vitamin B12, because harm from high intakes has not been shown. | 2 milligrams (2,000 micrograms) a day from supplements |
| Share of the limit | No limit to compare | 50% of the limit |
| Adults need | 2.4 micrograms a day | 1.5 micrograms a day |
Good to know
- People who eat no animal foods usually need a fortified food or a supplement to get enough.
Quick answers
- Is 1000 mcg of B12 too much?
- 1,000 micrograms of vitamin B12 has no set upper limit. That is about 417 times the adult RDA of 2.4 micrograms.
- What does the NHS say about 1,000 mcg of vitamin B12?
- 1,000 micrograms of vitamin B12 is within the NHS guidance of 2 milligrams (2,000 micrograms) a day from supplements. In the UK, adults need 1.5 micrograms a day.
- What is the upper limit for vitamin B12?
- US: No upper limit has been set for vitamin B12, because harm from high intakes has not been shown. UK (NHS): 2 milligrams (2,000 micrograms) a day from supplements.
Sources
- NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/ - NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/
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