Silicon (Orthosilicic Acid)
Also known as: orthosilicic acid, choline-stabilized orthosilicic acid (ch-OSA), choline-stabilised orthosilicic acid, CS-OSA, OSA-VC
Randomized trials of choline‑stabilised orthosilicic acid (ch‑OSA) report increased markers of type I collagen formation (PINP) versus calcium and vitamin D alone at 6 mg and 12 mg Si daily over 12 months, without clear dose response and without significant lumbar spine BMD change. A 12‑week trial in knee osteoarthritis found no effect in the overall population but a benefit on symptoms and cartilage biomarkers in men. A small peri‑implantitis trial reported stabilisation of peri‑implant bone measures and less mucosal recession versus placebo after surgery. Short pharmacokinetic work shows appreciable plasma and urinary appearance of Si after an OSA‑vanillin dose.
Last reviewed: 2026-10-14 · 5 indexed studies
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Overview
Oral orthosilicic acid (often stabilised with choline or vanillin) has been trialled as a dietary silicon source to support markers of bone and connective tissue health. Human trials report effects on biochemical markers of bone collagen and some measures of bone or peri‑implant tissue stability, but clinical benefits on bone mineral density are not established.
Mechanism & Function
Mechanism of Action
Silicon in the form of orthosilicic acid is proposed to support collagen synthesis and connective tissue matrix metabolism, which could translate to effects on bone collagen markers and tissue integrity. The human trials measured biochemical markers consistent with this pathway but do not establish clinical outcomes such as fracture risk reduction.
Physiological Role
Potential cofactor or substrate in collagen and extracellular matrix formation; involved in bone and connective tissue metabolism.
Primary Pathways
Performance / Health Relevance
Limited for athletic performance; any relevance is indirect through connective tissue or bone health rather than acute ergogenic effects.
Evidence Review
Compare Choline Forms
Full comparison4 choline forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.
| Form | Evidence |
|---|---|
Silicon (Orthosilicic Acid)This page Oral orthosilicic acid formulations showed measurable increases in plasma and urinary Si over 6 h, indicating absorption; stabilised forms (choline or vanillin complexes) aim to limit polymerisation and improve bioavailability. | 61/100 |
| Alpha-GPC Superior choline bioavailability vs CDP-choline or choline bitartrate | 78/100 |
| Choline (Choline Bitartrate) Choline bitartrate is well-absorbed, but significant first-pass metabolism can limit its systemic bioavailability for direct cholinergic effects compared to more advanced forms like CDP-choline or Alpha-GPC. | 60/100 |
| Citicoline Near-complete oral absorption; hydrolysed to choline and cytidine before crossing the blood-brain barrier. | 45/100 |
Practical Use & Dosage
- Minimum Effective Dose
- Approximately 6 mg elemental Si daily showed effects on a bone formation marker in a 12‑month RCT.
- Optimal Range
- Not established; trials used 3–12 mg Si/day (ch‑OSA).
- Upper / Caution Level
- Not established from provided abstracts.
- Timing
- Dosing schedules in trials were daily; one peri‑implantitis trial used twice daily capsules for 1 year.
- Best Format
- Choline‑stabilised orthosilicic acid (ch‑OSA) or orthosilicic acid complexes (e.g. vanillin‑stabilised) as oral capsules.
- Bioavailability
- Oral orthosilicic acid formulations showed measurable increases in plasma and urinary Si over 6 h, indicating absorption; stabilised forms (choline or vanillin complexes) aim to limit polymerisation and improve bioavailability.
- Absorption Considerations
- Orthosilicic acid can polymerise in concentrated or non‑neutral pH solutions; stabilised complexes were used in trials to preserve monomeric, absorbable Si.
Safety & Interactions
Side Effects
- •No ch‑OSA related adverse events reported in the cited long‑term RCTs
Who Should Avoid
- •People with known hypersensitivity to product excipients (e.g. choline preparations)
Monitoring
Standard biochemical safety parameters remained within normal range in the reported 12‑month trial; no routine specific monitoring indicated in the provided abstracts.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Silicon (Orthosilicic Acid) typically used or indicated?
Silicon (Orthosilicic Acid) is most commonly used for: Support bone health, Support connective tissue / joint health, Support mucosal and implant site healing. Potential cofactor or substrate in collagen and extracellular matrix formation; involved in bone and connective tissue metabolism.
How does Silicon (Orthosilicic Acid) work?
Silicon in the form of orthosilicic acid is proposed to support collagen synthesis and connective tissue matrix metabolism, which could translate to effects on bone collagen markers and tissue integrity. The human trials measured biochemical markers consistent with this pathway but do not establish clinical outcomes such as fracture risk reduction.
What is the recommended dose of Silicon (Orthosilicic Acid)?
The optimal range is Not established; trials used 3–12 mg Si/day (ch‑OSA).. with a minimum effective dose of Approximately 6 mg elemental Si daily showed effects on a bone formation marker in a 12‑month RCT.. Best taken: Dosing schedules in trials were daily; one peri‑implantitis trial used twice daily capsules for 1 year.. Upper / caution level: Not established from provided abstracts..
What are the side effects of Silicon (Orthosilicic Acid)?
Reported side effects include: No ch‑OSA related adverse events reported in the cited long‑term RCTs. Monitoring: Standard biochemical safety parameters remained within normal range in the reported 12‑month trial; no routine specific monitoring indicated in the provided abstracts.
Who should avoid Silicon (Orthosilicic Acid)?
Silicon (Orthosilicic Acid) is generally not recommended for: People with known hypersensitivity to product excipients (e.g. choline preparations).
How strong is the evidence for Silicon (Orthosilicic Acid)?
Evidence level: Moderate (overall score 61/100), based on 5 indexed studies on SuppIndex.
Research & References (5)
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.
12‑month double‑blind RCT in osteopenic women receiving calcium (1000 mg) and vitamin D3 (20 µg) plus ch‑OSA at doses providing 3, 6 or 12 mg Si/day or placebo; assessed bone turnover markers and BMD.
The effect of choline-stabilized orthosilicic acid in patients with peri-implantitis: an exploratory randomized, double-blind, placebo controlled study.
Exploratory randomized, double‑blind, placebo‑controlled study in patients with peri‑implantitis; patients had surgical treatment and then took CS‑OSA or placebo twice daily for 1 year; clinical and CBCT bone measures assessed.
A 12-week randomized, double-blind, placebo-controlled multicenter study of choline-stabilized orthosilicic acid in patients with symptomatic knee osteoarthritis.
12‑week multicentre, double‑blind RCT in 211 patients with knee osteoarthritis randomised to ch‑OSA or placebo; primary outcome WOMAC pain; secondary outcomes included WOMAC subscales and cartilage biomarkers CTX‑II and COMP.
Digestive absorption of silicon, supplemented as orthosilicic acid-vanillin complex.
Single‑centre, double‑blind, cross‑over RCT in 14 healthy subjects comparing an orthosilicic acid‑vanillin complex (OSA‑VC) to placebo; plasma and urinary Si measured over 6 h to assess absorption and excretion.
Silicon Supplementation for Bone Health: An Umbrella Review Attempting to Translate from Animals to Humans.
2024 umbrella review attempting to summarise silicon supplementation studies across species and translate to humans; assessed ranges of silicon intakes and effects on bone and mineral metabolism.
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Zinc
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Research Overview
Moderate EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/silicon-orthosilicic-acid
SuppIndex. (2026). Silicon (Orthosilicic Acid): Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/silicon-orthosilicic-acid
Based on 5 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Was administered alongside calcium and vitamin D in at least one trial; interactions with common supplements were not reported in the provided studies.