Silicon / Orthosilicic Acid

Evidence Level
Limited
2 Clinical Trials
4 Documented Benefits
2/5 Evidence Score

Silicon is one of the most abundant elements on earth and the third most abundant trace element in the human body — yet its essentiality in humans remains debated. Bioavailable silicon (as orthosilicic acid, OSA) accumulates in connective tissues — bone, cartilage, skin, hair, and nails — where it appears to stimulate collagen synthesis and cross-linking, and is associated with bone mineral density in population studies. ch-OSA® (BioMinerals) stabilized orthosilicic acid choline-chelate is the most bioavailable and clinically studied silicon supplement form.

Studied Dose 10–40 mg/day bioavailable silicon as ch-OSA®; dietary silicon: 20–50 mg/day from grains, beer, water; horsetail extract doses vary widely in bioavailability
Active Compound Orthosilicic acid (OSA, Si(OH)₄) — ch-OSA® (choline-stabilized orthosilicic acid, BioMinerals NV) provides ~10 mg bioavailable silicon; horsetail extract provides less bioavailable silica (SiO₂)

Bone mineral density support

Population studies consistently show positive associations between dietary silicon intake and bone mineral density in both pre- and postmenopausal women and men. A 2-year RCT with ch-OSA® showed significant improvements in bone collagen markers (CICP) and a trend toward improved bone mineral density — suggesting silicon supports the collagen matrix component of bone rather than just mineral density.

Collagen synthesis stimulation

Orthosilicic acid stimulates collagen type 1 synthesis in osteoblasts, fibroblasts, and chondrocytes — the structural protein scaffold upon which bone mineral is deposited. Prolyl hydroxylase (the collagen-crosslinking enzyme) requires silicon for optimal activity, providing a mechanistic explanation for silicon's bone and connective tissue effects.

Skin, hair, and nail quality improvement

ch-OSA® RCTs in women with photoaged skin showed significant improvements in skin microrelief, skin elasticity, and hair tensile strength after 20 weeks — attributed to increased dermal collagen synthesis. Silicon's role in cross-linking structural proteins (collagen, elastin, glycosaminoglycans) explains its cosmetic skin and hair applications.

Aluminum detoxification

Orthosilicic acid forms stable, non-absorbable aluminosilicate complexes in the GI tract and may reduce aluminum absorption from diet and water. Population studies suggest silicon-rich drinking water reduces Alzheimer's disease risk — potentially through aluminum-silicate formation preventing aluminum's neurotoxic accumulation.

1

Prolyl hydroxylase activation and collagen crosslinking

Orthosilicic acid appears to stabilize prolyl hydroxylase — the enzyme that hydroxylates proline residues in procollagen, enabling hydroxyproline formation essential for collagen triple helix stability and crosslinking. Silicon may also interact directly with the hydroxyl groups of collagen and glycosaminoglycans, stabilizing the extracellular matrix structure.

2

Osteoblast collagen gene expression upregulation

OSA at physiological concentrations stimulates osteoblasts to increase expression of collagen type 1 alpha-1 (COL1A1) and osteocalcin genes, and activates osteoblast differentiation markers. This direct osteoblast stimulation explains silicon's effects on the organic (protein) component of bone matrix — complementary to calcium's effects on the inorganic mineral component.

3

Aluminosilicate formation and neuroprotection

Silicon and aluminum form insoluble aluminosilicate complexes at physiological pH. In the GI tract, dietary silicon reduces aluminum absorption by forming these complexes before intestinal absorption can occur. Systemically, silicon may facilitate urinary aluminum excretion, potentially protecting neural tissue from aluminum-mediated toxicity.

1
ch-OSA® and Bone Collagen Synthesis — RCT
PubMed

Randomized, double-blind, placebo-controlled trial of ch-OSA® (10 mg/day bioavailable silicon) vs. placebo combined with calcium + vitamin D3 in 136 osteopenic women for 12 months.

136 osteopenic women. 12-month intervention.

ch-OSA® significantly improved CICP (bone collagen synthesis marker) by 22% vs. placebo + calcium/D3. Trend toward improved femoral neck BMD. Supports silicon as bone collagen-targeting supplement complementary to calcium.

2
ch-OSA® and Skin/Hair Quality — RCT
PubMed

Randomized, double-blind, placebo-controlled trial of ch-OSA® (10 mg/day silicon) in 50 women with photoaged skin for 20 weeks.

50 women with photoaged facial skin. 20-week cosmetic study.

ch-OSA® significantly improved skin microrelief score, skin roughness, and skin elasticity vs. placebo. Hair tensile strength significantly improved. Nail brittleness reduced. Confirms silicon's structural role in connective tissue cosmetic outcomes.

Common Potential side effects

ch-OSA® and orthosilicic acid: excellent safety profile at studied doses
High-dose crystalline silica (SiO₂, industrial form) causes silicosis when inhaled — NOT relevant to dietary supplementation
Very rare GI discomfort at high doses of inorganic silica supplements

Important Drug interactions

No established pharmacokinetic drug interactions for orthosilicic acid at supplemental doses
Aluminum-containing antacids/medications — silicon forms insoluble aluminosilicates; may reduce aluminum drug absorption if taken simultaneously; separate doses by 2 hours