Maximum Recommended Daily Consumption of Selenium
The maximum dose of selenium in a supplement should not exceed 200 micrograms per day, as there is only a narrow margin between safe and toxic dosages. 1
Understanding Selenium Requirements and Safety
Selenium is an essential mineral that contributes to antioxidant defense mechanisms in the body. It plays important roles in:
- Immune function
- Antioxidant protection
- Thyroid hormone metabolism
Safe Upper Limit
The American Cancer Society guidelines consistently recommend that selenium supplementation should not exceed 200 micrograms per day due to the narrow margin between therapeutic and toxic doses 1. This recommendation is supported by multiple guidelines and has remained consistent over time.
Sources of Selenium
Good dietary sources of selenium include:
- Seafood
- Meats
- Grain products
For most individuals, these food sources provide adequate selenium without the need for supplementation.
Special Considerations for Different Populations
General Population
- For most healthy adults, the recommended daily intake ranges from 60-70 μg/day 2
- Supplements containing 200 micrograms per day are generally considered safe and adequate for an adult of average weight on a typical diet 3
Higher Risk Groups
Some populations may require higher selenium intake, but should still not exceed the 200 mcg/day maximum in supplement form:
- Patients on parenteral nutrition: 60-100 mcg/day is typically sufficient 4
- Patients with documented deficiency: May require up to 200 mcg/day with monitoring 5
- Burns patients: May benefit from higher doses (around 375 mcg/day) under medical supervision 1
- Trauma patients: May benefit from supplements of 275 mcg/day under medical supervision 1
Monitoring and Toxicity
Signs of Toxicity
Upper limits for plasma selenium before toxicity symptoms occur range from about 6 μmol/L to 12 μmol/L 1. Recent research indicates that selenium overexposure is associated with:
- Type 2 diabetes
- High-grade prostate cancer
Assessment of Selenium Status
When monitoring selenium status, particularly in clinical settings:
- Blood selenium measurement is the primary method
- Values <0.4 μmol/L indicate definite deficiency
- Values <0.75 μmol/L in patients without inflammation may warrant supplementation
- CRP levels should be considered when interpreting selenium values, as inflammation affects levels 1, 5
Historical Perspective
Earlier research from the 1970s suggested maximum acceptable daily intake levels of up to 500 μg 6, but more recent evidence has led to the more conservative recommendation of 200 μg as the maximum supplement dose 1.
Caution
While selenium is essential for health, high-dose selenium supplements are not recommended without medical supervision due to the narrow margin between beneficial and toxic doses. The evidence consistently supports 200 micrograms per day as the maximum safe supplemental dose for the general population.