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 among the most bioavailable and clinically studied silicon supplement forms.

Studied Dose 10-40 mg/day bioavailable silicon as ch-OSA®; dietary silicon: 20-50 mg/day.
Active Compound Orthosilicic acid (OSA, Si(OH)₄) — ch-OSA® (choline-stabilized OSA, BioMinerals NV) provides ~10 mg bioavailable silicon; horsetail provides less bioavailable silica (SiO₂).

Benefits

Bone mineral density support

Population studies consistently show positive associations between dietary silicon intake and bone mineral density in 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. Silicon has been proposed to support prolyl hydroxylase (an enzyme involved in collagen maturation) and matrix stability, offering a possible mechanistic explanation for its 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 binding in the digestive tract

Orthosilicic acid forms stable, non-absorbable aluminosilicate complexes in the GI tract and may reduce aluminum absorption from diet and water. Some observational studies have looked at associations between silicon-rich drinking water and cognitive aging, but the underlying aluminum-neurotoxicity hypothesis remains scientifically contested and unproven. Silicon supplements are not intended to treat or prevent any neurological disease.

Mechanism of action

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 aluminum binding

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. Some research suggests silicon may modestly increase urinary aluminum excretion. Any downstream health significance of this is unproven, and the link between aluminum and neurological disease remains contested.

Clinical trials

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 increased a marker of type I collagen (bone) formation versus placebo plus calcium/vitamin D3. A favorable but non-significant femoral-neck BMD trend in a post-hoc subgroup. 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.

Side effects and drug interactions

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

Frequently asked questions about Silicon / Orthosilicic Acid

What is silicon (silica) used for?

Silicon, often taken as silica or orthosilicic acid, is studied for supporting skin, hair, nails, bone, and connective tissue, since it plays a role in collagen formation. It is a popular ingredient in beauty-from-within supplements.

How much silicon should I take?

There is no official RDA, but typical intakes are 20 to 50 mg per day from food (whole grains, vegetables, and water). Supplements often provide around 5 to 20 mg of bioavailable silicon. Choline-stabilized orthosilicic acid is a well-absorbed form.

Does silicon help hair, skin, and nails?

Some studies of well-absorbed silicon (like orthosilicic acid) suggest benefits for hair strength, nail quality, and skin elasticity, likely via its role in collagen. Effects are modest and build over months of consistent use.

Is silicon safe?

Dietary and supplemental silicon are generally very safe; the body excretes excess in urine. Choose well-absorbed forms for benefit. As with any supplement, those who are pregnant or on medication should check with a doctor.

What is Silicon / Orthosilicic Acid?

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.

What is Silicon / Orthosilicic Acid used for?

Silicon / Orthosilicic Acid is researched primarily for Bone Health and Hair, Skin & Nails. Population studies consistently show positive associations between dietary silicon intake and bone mineral density in pre- and postmenopausal women and men.

What is the recommended dosage of Silicon / Orthosilicic Acid?

The clinically studied dose is 10-40 mg/day bioavailable silicon as ch-OSA®; dietary silicon: 20-50 mg/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Silicon / Orthosilicic Acid safe, and does it have side effects?

For most healthy adults, Silicon / Orthosilicic Acid is well tolerated at studied doses. Reported effects can include: 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 It may also interact with some medications. Silicon / Orthosilicic Acid is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Silicon / Orthosilicic Acid interact with any medications?

Possible interactions include: 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 If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Silicon / Orthosilicic Acid?

NutraSmarts rates the evidence for Silicon / Orthosilicic Acid as Limited (2 out of 5). It is backed by 2 clinical trials and 3 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(3 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Spector TD, Calomme MR, Anderson SH, Clement G, Bevan L, Demeester N, Swaminathan R, Jugdaohsingh R, Berghe DA, Powell JJ Choline-stabilized orthosilicic acid supplementation as an adjunct to calcium/vitamin D3 stimulates markers of bone formation in osteopenic females: a randomized, placebo-controlled trial BMC Musculoskeletal Disorders. 2008;9:85. doi: 10.1186/1471-2474-9-85.PubMedUsed to support: Human RCT showing ch-OSA (choline-stabilized orthosilicic acid) supplementation significantly increases bone collagen markers and bone-specific alkaline phosphatase in osteopenic women, directly supporting 'Bone mineral density support' and 'Collagen synthesis stimulation'.
  2. Barel A, Calomme M, Timchenko A, De Paepe K, Demeester N, Rogiers V, Clarys P, Vanden Berghe D Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin Archives of Dermatological Research. 2005;297(4):147-53. doi: 10.1007/s00403-005-0584-6.PubMedUsed to support: Human RCT demonstrating oral ch-OSA supplementation improved skin roughness, elasticity, and nail brittleness, directly supporting 'Skin, hair, and nail quality improvement'.
  3. Rondanelli M, Faliva MA, Peroni G, Gasparri C, Perna S, Riva A, Petrangolini G, Tartara A Silicon: A neglected micronutrient essential for bone health Experimental Biology and Medicine. 2021;246(13):1500-1511. doi: 10.1177/1535370221997072.PubMedUsed to support: Review synthesizing human and mechanistic evidence that silicon is essential for bone collagen cross-linking and mineralization, supporting 'Bone mineral density support' and 'Collagen synthesis stimulation'.