An Excellent Source of Calcium. Silicon May Support Bone Health. Gluten, Wheat & Dairy Free. Suitable for Vegetarians. Silica obtained from marine-derived Red Algae Powder (Lithothamnium coralloides) is a source of the natural trace element silicon. Silicon is found in many unrefined grains and in some seafood sources, including mussels. Silicon intake has been positively associated with bone health.