This month we reveal Selenium – a micronutrient – we only require 55ug per day, but it is still vital for healthy bodily function. It’s an important cofactor for Vitamin E, controls thyroid hormones. As you might expect, being a Group 6 element just below Sulfur, Selenium compounds stink. It is mainly present as the Selenium analogue of methionine, and the Selenium analogue of methional, the Strecker aldehyde, is reported to be one of the worst smells in the world.