Is 200 mcg of selenium too much?
200 micrograms of selenium is within the adult upper limit of 400 micrograms a day. That is about 3.6 times the adult RDA of 55 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
200 micrograms of selenium is within the NHS guidance of 350 micrograms a day from supplements. In the UK, adults need 75 micrograms a day for men and 60 micrograms for women.
The figures
| US (NIH) | UK (NHS) | |
|---|---|---|
| Amount checked | 200 mcg | |
| Answer | Within the upper limit | Within NHS guidance |
| Compared with | 400 micrograms a day | 350 micrograms a day from supplements |
| Share of the limit | 50% of the limit | 57% of the limit |
| Adults need | 55 micrograms a day | 75 micrograms a day for men and 60 micrograms for women |
Quick answers
- Is 200 mcg of selenium too much?
- 200 micrograms of selenium is within the adult upper limit of 400 micrograms a day. That is about 3.6 times the adult RDA of 55 micrograms.
- What does the NHS say about 200 mcg of selenium?
- 200 micrograms of selenium is within the NHS guidance of 350 micrograms a day from supplements. In the UK, adults need 75 micrograms a day for men and 60 micrograms for women.
- What is the upper limit for selenium?
- US: 400 micrograms a day. UK (NHS): 350 micrograms a day from supplements.
Sources
- NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/ - NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/others/
Ask Supplement Check yourself
Type any amount of a vitamin, mineral or supplement, or a whole routine, and see how it compares with the adult limits. Open Supplement Check, free, no sign-up.
In Claude or any app that takes MCP connectors, add https://goodturn-mcp.pages.dev/supplementcheck/mcp and ask: “Is 200 mcg of selenium too much?”