Dietary silicon and bone health

Silicon (Si) is the third most abundant trace element of the human body and is especially associated with connective tissues such as in bone, skin and blood vessels. Dietary Si is predominately derived from plant-foods and, generally, is readily broken down and absorbed in the gastrointestinal tract in the form of orthosilicic acid. Cereals and cereal products (especially beer), green beans and some mineral water are examples of major dietary sources of Si. The majority of absorbed Si is then excreted in urine although some is taken up into tissues. Average Si intakes are around 25 mg/day in the Western World. In this review, dietary sources of Si, its metabolism and evidence for its biological role in bone health are presented.