Silicon is found in most plants, animals, and most living organisms. It is not considered an essential nutrient and deficiencies are rare. The richest sources of silicon are cereal products and unrefined grains of high fiber content. Significant amounts of silicon in the diet occur in the form of silicon dioxide (silica), which is poorly absorbed. Animal foods are low in silicon. Preliminary reserach has demonstrated that silicon is beneficial to the hair, skin, nails, and bones.