Quote: “Pluck almost any cell from your body, and it will have a million or more selenium atoms in it, yet until recently nobody had any idea what they were there for. We now know that selenium makes two vital enzymes, deficiency in which has been linked to hypertension, arthritis, anaemia, some cancers, and, even, possibly reduced sperm counts. So, clearly, it is a good idea to get some selenium inside you (it is found particularly in nuts, whole meal bread, and fish), but at the same time, if you take too much, you can irremediably poison your liver. As with much of life, getting the balances right is a delicate business.” End Quote.
The above lines are quoted from Bill Bryson’s book The Body: A Guide for Occupants. ISBN-13: 978-0385539302. I can recommend the book highly. Bryson writes an English that is a pleasure to read, and the book is full of facts and relationships. You may already know him from his earlier book about science and technology, The Short History of Almost Everything.