Function:
Selenium is needed for the proper function of antioxidant enzymes.

Recommended Dietary Allowance:
55 mcg per day for both women and men.

Deficiency:
Deficiency is unusual, seen most often in China in areas with low soil selenium content. Its most serious manifestation is weakening and enlargement of the heart.

Sources:
Food sources include vegetables grown in selenium rich soil, some seafood, liver, meat, nuts, and grains.

Toxicity and UL:
Toxic symptoms include hair loss, fingernail and toenail damage.

The UL for selenium is 400 mcg per day

Recommendation:
Studies have been done suggesting an anticancer effect from doses of selenium between 50 and 200 mcg per day. The Arizona Cancer Center did a trial in 1312 patients with skin cancer and showed that selenium 200 mcg per day reduced the risk of other cancers developing though not affecting the course of the primary skin cancer.

50 to 200 mcg per day have not been associated with any health problems and consideration should be given to supplementation at this level.

For more information visit:
http://osu.orst.edu/dept/lpi/infocenter/minerals/selenium/