Silicon

The accumulation of silicon (Si) in animal bones has been documented since the 1970s but to date there has been no recognition of its essentiality in humans.This is despite the knowledge that Si is consumed and absorbed daily, its distribution is consistent with its hypothesised physiological role, and deficiency can produce a characteristic picture correctable with Si supplementation. Instead, Si is currently relegated to the ranks of the ultra trace minerals, together with arsenic, boron and vanadium, which, while not essential, share the descriptor of 'beneficial to human health'. Like many of these minerals, the chemical form they take determines both therapeutic and toxic potential. Silicon is the basis for popular supplements marketed for hair and skin health. Rachel Arthur investigates.