Supplements are a great way to ensure proper selenium intake, but there are differences among them. Selenium comes in many forms. Most selenium supplements are selenium yeast, selenomethionine, selenite and selenate. Selenite and selenate are both inorganic forms of selenium and have an absorption rate of about 50%. This unfortunately, increases the chance of selenium toxicity. For this reason alone, organic forms of selenium, such as selenium yeast or selenomethionine, are safer and are more readily absorbed. In fact, organic forms of selenium are the only way to raise serum levels of selenium within the body. This is attributed to their bioavailability. When using organic forms of selenium, current research shows that doses up to 1600 mcg a day were well tolerated with no signs of toxicity although most experts recommend upper tolerable limits to be 400-600 mcg a day. Selenium yeast does have a higher absorption rate, (about 60-70%), than that of selenite or selenate. Yet some manufacturers simply add inorganic selenium to yeast products, so caution is necessary when taking such products. In addition, those with candida issues may want to avoid yeast type supplements as their specific symptoms could be compounded. Of the selenium supplements, selenomethionine has the best bioavailability with an absorption rate of 90%. It is organic and yeast free. When compared with other selenium supplements selenomethionine proves to be the most applicable and safest for long-term therapeutic use.
The beneficial nature of selenium supplementation cannot be underscored. For most, 200-400mcg of selenium will prove to be sufficient. Those with amalgam fillings or those supplementing with iodine may need more. As with most supplements, selenium can have toxic effects when used in excess. Symptoms of selenium toxicity include diarrhea, hair loss, brittle nails, and other gastro-intestinal upset. To reduce the risk of toxicity it is recommended to start with 200mcg working toward the upper tolerable limits of 400-600mcg of organic selenium. Careful and proper supplementation with selenium is a wise decision for those who suffer thyroid and auto-immune disorders as it works to correct imbalances in thyroid functioning and immune response.
