Bioavailability of Silicon from Three Sources

ince the early 1970s, scientific evidence has shown that silicon is an essential nutrient for higher animals, including humans. Its role in human physiology is not fully defined, but it appears to be required for optimal growth and development of bone, cartilage, and connective tissues. Both metabolic and structural roles have been proposed. In bone, silicon is localized in active growth areas where it is thought to promote growth and mineralization. In cartilage and connective tissues, silicon is thought to form cross-links with proteoglycan complexes that interlace with collagen and contribute to structural integrity. Silicon also appears to promote collagen synthesis. Given its nature as an essential nutrient, silicon is often included in mineral supplements. Sources include sodium metasilicate, calcium silicate, and ground horsetail grass or Equisetum arvense. However, little scientific information exists on the relative bioavailability of silicon from these sources. This comparative study was undertaken to provide such information for three silicon sources: calcium silicate, horsetail grass, and silicon amino acid complex.