Evidence Level
Emerging
Silicon/silica research for supplementation is still emerging. The strongest evidence comes from the Barel et al. (2005) double-blind RCT showing ch-OSA improved skin, hair, and nails over 20 weeks. Epidemiological data is supportive: the Framingham Offspring study (Jugdaohsingh et al., 2004, n=2,847) found a strong positive association between dietary silicon intake and bone mineral density, with the highest silicon quartile having significantly higher hip BMD than the lowest. However, interventional trials on bone density are limited. Reffitt et al. (2003) showed orthosilicic acid stimulated collagen type I synthesis in human osteoblasts in vitro, providing mechanistic support.