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.
A large (about 500 participants) double-blind, placebo-controlled study failed to find that use of selenium supplements at 100 mcg, 200 mcg, or 300 mcg daily improved mood or general well-being . 59. A study of 197 people with moderately severe asthma failed to find benefit with selenium (100 mcg daily).