Balancing chemical equations is a key chemistry skill. Use these step by step instructions to write and balance chemical equations. Balancing chemical equations is a key chemistry skill. Use these step by step instructions to write and balance chemical equations.
So, there are many signs and symptoms of Selenium Overdose- some occur very early and some occur much later. 1  Early Signs: Some of the early signs of Selenium Toxicity are endocrine hormone disturbances- particularly thyroid issues. Poor hair and nail growth are early signs that are probably the easiest to notice.
Some research shows that taking 400 mcg of selenium daily for 2 years or 100 mcg of selenium along with zinc, vitamin C, vitamin E, and beta-carotene daily for 7.5 years does not reduce the risk of developing cancer. However, other research suggests taking selenium might reduce the risk of cancer-related death.