Silicon
Silicon is yet another essential trace element and like so many others its properties are only just beginning to be fully understood.
It is thought that Silicon plays an important part in the formation of human connective tissues, bones, skin and fingernails.
Good natural sources are whole grains, vegetables and seafood. It is also present in hard water areas so there are some benefits to the water that gives us all that limescale.
There are no specific symptoms of deficiency although brittle bones, weakened nails and hair and poor skin condition may all be symptoms.
There are no official figures for RDA in US although it is thought that we need between 20 & 30 mg per day. Although Silicon is toxic if inhaled there is no evidence of toxicity in food or normal supplementation.