Silica, a mineral form of silicon, is a dietary supplement used for bone, skin, hair and nails; food and certain mineral waters supply it. People eating more silicon tend to have denser hips; small maker-linked trials showed better skin and hair, but none was independently repeated or examined fractures. Dietary silicon is low-risk; problems arise mainly with kidney failure, horsetail products and inhaled powders. Supplement benefits remain plausible but unproven. (Full Review)
| Marker | Target | Why |
|---|---|---|
| eGFR and creatinine | eGFR above 90 mL/min/1.73 m² | Confirms silicon clearance |
| Serum potassium | 4.0–5.0 mmol/L | Detects diuretic losses (horsetail users only) |
| Urinary silicon (24-hour) | No established target; track rise from own baseline | Confirms absorption |
| Bone mineral density (DEXA) | T-score above −1.0 | Tracks bone outcome |
| PINP | No established functional target; track change from own baseline | Measures bone formation |
| CTX | Lower half of premenopausal reference range | Measures bone breakdown |
| Whole-blood vitamin B1 | Upper half of lab reference range | Detects thiaminase effect (horsetail users only) |
| Urinalysis | No blood or crystals | Screens for stones |
Cadence: Urinary silicon at 4–8 weeks; potassium at 2–4 weeks for horsetail users on diuretics; kidney function every 6–12 months; bone-turnover markers at 6 and 12 months; bone density every 12–24 months