Silica, primarily in the form of silicon dioxide, is found naturally in many foods and is a common component of dietary supplements marketed for supporting the structural system—bones, joints, hair, skin, and nails. The rationale for its use stems from the role of silicon, an essential trace element, in connective tissue health and bone formation. Several animal studies and limited human research suggest that silicon is involved in collagen synthesis and bone mineralization. For example, observational studies have shown correlations between higher dietary silicon intake and improved bone mineral density, particularly in premenopausal women. Additionally, silicon is known to play a role in the formation of glycosaminoglycans, which are important for cartilage and connective tissue structure.

However, direct clinical evidence demonstrating that silica supplementation leads to measurable improvements in bone strength or joint health in humans is limited and often inconclusive. Most human studies are small, short-term, or observational rather than randomized controlled trials. As a result, while there is some scientific basis for the use of silica in support of the structural system, the overall quality and quantity of evidence remains modest, and authoritative organizations do not currently recommend silica supplementation for bone or joint health in the general population.