Supplement
Silica is a form of silicon, a trace mineral in connective tissue thought to help build skin, bone, and hair. People mostly look at it as supportive care for hair-pulling disorder, and the evidence is limited: small human trials of a stabilized form found modest gains in hair strength and less brittle nails. The gains were modest and the studies small, so they say little about hair-pulling itself.
Sources: PMID 14750728; PMID 30189931
- Updated
- How we grade
- 3 studies cited
- Best evidence
- Grade C
- Conditions studied
- 1
- Outcomes
- 4
- Graded outcomes
- 0022
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bone Mineral Density Population-based epidemiological studies (including Framingham cohort data) link higher dietary silicon intake with better bone mineral density, particularly in premenopausal women. One RCT in osteopenic women showed improvement in bone formation markers with ch-OSA added to calcium/vitamin D supplementation versus calcium/vitamin D alone. | Improves (the measure goes up) | Small effect | 3 studies | 300 people | ||
Studies that measured bone mineral density
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General
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair and Nail Quality Small human trials of choline-stabilized orthosilicic acid (ch-OSA) showed modest improvements in hair tensile strength and reduced nail brittleness. Effects were statistically significant but not dramatic, and study sample sizes were limited. | Improves (the measure goes up) | Small effect | 2 studies | 120 people | ||
Studies that measured hair and nail quality | ||||||
| Skin Elasticity Limited data from a small human study suggests ch-OSA supplementation may improve skin elasticity and reduce skin roughness. Silicon is a component of glycosaminoglycans in connective tissue, providing a plausible mechanism, but clinical evidence remains preliminary. | Improves (the measure goes up) | Small effect | 2 studies | 50 people | ||
Studies that measured skin elasticity | ||||||
| Aluminum Absorption Mechanistic and preclinical studies suggest silicon may bind dietary aluminum and reduce its gastrointestinal absorption or increase urinary excretion. This has theoretical relevance for aluminum-related neurotoxicity, but clinical evidence in humans is lacking. | Changes; see studies | Small effect | 2 studies | |||
Studies that measured aluminum absorption | ||||||
Key findings
- Bone Mineral DensityImproves (the measure goes up)
- Hair and Nail QualityImproves (the measure goes up)
- Skin ElasticityImproves (the measure goes up)
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- Grade C
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Studies cited
3 studies from PubMed
- Water-Dispersible Rhodamine B Hydrazide Loaded TiO₂ Nanoparticles for Turn On Fluorimetric Detection and Imaging of Orthosilicic Acid Accumulation In-Vitro in Nephrotoxic Kidney Cells.
- Secondary structure and dynamics study of the intrinsically disordered silica-mineralizing peptide P(5) S(3) during silicic acid condensation and silica decondensation.
- Emission, fate and effects of soluble silicates (waterglass) in the aquatic environment.