Silicon

What is Silicon?

Silicon is a non-metallic trace element that, in biological systems, exists predominantly as orthosilicic acid — the monomeric, water-soluble form that the body can absorb and utilize. Though not yet classified as an officially essential nutrient for humans, silicon concentrations are highest in metabolically active connective tissues including bone, cartilage, skin, and arterial walls, suggesting a functional role. Dietary intake occurs mainly through plant foods, beer, and drinking water, with bioavailability varying widely depending on the food matrix and chemical form of silicon.

How does Silicon work?

Silicon appears to stimulate collagen type I synthesis in osteoblasts (bone-forming cells) and fibroblasts (skin connective tissue cells), contributing to the structural integrity of bone matrix and dermal tissue. It is believed to cross-link glycosaminoglycans and collagen fibers in the extracellular matrix, enhancing tissue tensile strength. Silicon may also influence hydroxyapatite crystal formation during bone mineralization, positioning it as a potential cofactor in skeletal development and repair.

What forms does Silicon come in?

Orthosilicic acid liquid supplements and ch-OSA capsules offer the highest bioavailability. Horsetail-derived silica capsules are widely available but have variable absorption. Colloidal silica (silicon dioxide in particle form) has low solubility and limited absorption. Dietary silicon from plant foods and beer represents the main population-level source. For therapeutic purposes, ch-OSA or stabilized orthosilicic acid formulations are preferred based on available evidence.

Where it comes from:

Silicon's potential biological role was first systematically investigated in the 1970s when Carlisle (1972) and Schwarz & Milne (1972) independently reported that silicon deprivation in chicks and rats resulted in skeletal abnormalities, spurring interest in its function in connective tissue. Human research accelerated in the early 2000s with the development of stabilized orthosilicic acid formulations that enabled controlled clinical trials.

What does Silicon help with?

• Bone Loss / Low Bone Mineral Density: Silicon is incorporated into the organic matrix of bone where it stimulates osteoblast activity and collagen type I synthesis, both critical for laying down new bone tissue. Epidemiological data from the Framingham Offspring Cohort Study (Jugdaohsingh et al., 2004, Journal of Bone and Mineral Research, n=2847) found significant positive associations between dietary silicon intake and bone mineral density at the hip in men and premenopausal women. A pilot randomized controlled trial by Spector et al. (2008, BMC Musculoskeletal Disorders, n=136) using ch-OSA in postmenopausal women with low bone density found that ch-OSA combined with calcium and vitamin D produced a non-statistically-significant trend toward greater improvement in bone collagen turnover markers compared to calcium and vitamin D alone; the study was underpowered, and larger trials are needed to confirm efficacy.
• Skin Aging & Reduced Elasticity: Silicon, as orthosilicic acid, stimulates fibroblast production of type I collagen and may influence cross-linking of collagen fibers in the dermis, contributing to improved skin firmness and hydration. A double-blind, placebo-controlled trial by Barel et al. (2005, Archives of Dermatological Research, n=50) found that 10 mg/day of ch-OSA for 20 weeks produced statistically significant improvements in skin roughness and skin elasticity compared to placebo in women with photoaged skin. A subsequent study by Zouboulis et al. (2012, Skin Pharmacology and Physiology) also reported positive effects of ch-OSA supplementation on skin surface and elasticity parameters, corroborating the Barel findings.
• Brittle Hair & Nails: Silicon is a structural component of hair shaft and nail plate, and orthosilicic acid supplementation may improve the mechanical properties of these keratinized tissues by enhancing the underlying connective tissue matrix from which they grow. The Barel et al. (2005) RCT also assessed hair and nail parameters, reporting that ch-OSA (10 mg/day for 20 weeks) significantly improved nail brittleness scores and increased hair tensile strength compared to placebo. These outcomes are mechanistically consistent with silicon's known role in collagen and glycosaminoglycan cross-linking in the dermal papilla region.
• Joint & Connective Tissue Support: Cartilage and synovial tissue contain glycosaminoglycans (such as hyaluronic acid and chondroitin) whose structural integrity may depend partly on silicon-mediated cross-linking. Silicon has been proposed to reduce joint degradation by supporting the extracellular matrix of cartilage, though direct human RCT evidence for joint pain outcomes specifically from silicon supplementation is limited. Most supporting data comes from the epidemiological associations between dietary silicon and connective tissue health, as well as the mechanistic collagen synthesis data from skin trials, rather than dedicated osteoarthritis RCTs.

What can Silicon help prevent?

• Age-related decline in bone mineral density (supported by epidemiological evidence showing inverse association between dietary silicon intake and bone loss in premenopausal women and men)

Which foods are rich in Silicon?

1. Whole Grain Cereals (oats, barley, rye): Whole grains are among the richest dietary sources of silicon, delivering it primarily as silicic acid esters bound to fiber; oat bran in particular contains high silicon concentrations and has measurable bioavailability.
2. Beer: Beer, particularly ales made from malted barley and hops, is recognized as one of the highest bioavailable dietary sources of silicon (as orthosilicic acid) due to the brewing process releasing monomeric silicic acid into aqueous solution; Jugdaohsingh et al. (2004) identified beer as a significant contributor to dietary silicon intake in populations.
3. Green Beans (French Beans): Green beans are among the vegetables with highest silicon content per serving, with silicon occurring in forms with reasonable bioavailability compared to cereal-bound silica.
4. Bananas: Bananas provide moderate amounts of dietary silicon and have been specifically noted in studies of dietary silicon sources as a contributing fruit-based source.
5. Mineral Water (silicon-rich varieties): Certain mineral waters, particularly those from silica-rich geological regions, contain orthosilicic acid in a directly bioavailable monomeric form; silicon content in water varies widely by source and can contribute meaningfully to daily intake.

Practical Tips:

Silicon bioavailability differs substantially by food matrix: silicon in water and beer (as monomeric orthosilicic acid) is the most bioavailable, while silicon in plant foods bound to fiber or phytate is less readily absorbed. Cooking can partially release plant-bound silica. High-fiber diets including whole grains and vegetables naturally optimize dietary silicon intake across the day.

What are the side effects of Silicon?

• Gastrointestinal discomfort (rare, reported anecdotally at high doses)
• Theoretical risk of kidney stone formation (silica urolithiasis) with very high supplemental doses in susceptible individuals — not documented in RCT doses
• No significant adverse events reported in published clinical trials at 10 mg/day ch-OSA for up to 20 weeks

Good to know:

Silicon at dietary levels and at supplemental doses studied in clinical trials (up to 10-20 mg/day as ch-OSA) has an excellent safety profile with no clinically significant adverse effects reported in published RCTs. Very high-dose supplementation is poorly studied in humans; inhaled crystalline silica (occupational exposure) is a known carcinogen and lung hazard, but this is entirely distinct from dietary or supplemental silicon and not relevant to oral supplementation.

How much Silicon should you take?

• Recommended daily: 10–25 mg/day of bioavailable silicon (as orthosilicic acid or ch-OSA); typical dietary intake ranges from 20–50 mg/day in Western diets. Clinical trials have primarily used 10 mg/day as ch-OSA. No official RDA has been established for silicon.
• Best time of day: No established time-of-day preference; taking with meals may reduce any gastrointestinal sensitivity, though ch-OSA liquid formulations are often taken before meals per product instructions.
• With or without food: Can be taken with or without food; liquid orthosilicic acid formulations are typically taken diluted in water. Taking with calcium-rich meals is unlikely to impair absorption based on current data.
• Time to effect: Skin and nail improvements: approximately 20 weeks of consistent supplementation. Bone density effects: 12 months or longer based on bone remodeling cycle timelines.
• How long to take it: No evidence supports cycling; continuous supplementation appears appropriate for ongoing bone and connective tissue support goals. Reassess after 6–12 months based on outcomes.