Silicon: The Often-Overlooked Structural Mineral
Silicon (Si) is the second most abundant element in the Earth's crust, yet its biological role in humans has only been systematically studied since the 1970s. Evidence suggests silicon is involved in bone mineralisation, collagen synthesis and connective tissue integrity. For supplement users, the critical question is not whether silicon is important but whether what is in the bottle actually gets absorbed — and here, the differences between forms are dramatic.
What Limits Silicon Absorption
The principal limiting factor for silicon absorption is the chemical form of the silicon compound. Silicon in the form of silicon dioxide (SiO2), which is used in many supplements and foods as an anti-caking agent, has poor bioaccessibility because it does not readily dissolve into the bioavailable monomeric form in the gut. Silicon must be converted to orthosilicic acid (Si(OH)4) to be absorbed through the intestinal epithelium.
A controlled study comparing urinary silicon excretion (a proxy for absorption) across different silicon sources found that orthosilicic acid from beer and some mineral waters was substantially more bioavailable than silicon from food sources like bananas or green beans, which contain silicon bound to fibre (Jugdaohsingh et al., 2000). This finding highlights that form matters more than dose for silicon.
Cofactors That Help
Vitamin C may support silicon's role in collagen synthesis indirectly: both are involved in the same collagen-producing pathway. There is no strong evidence that vitamin C directly enhances silicon absorption, but taking a supplement aimed at connective tissue support alongside dietary vitamin C is rational from a mechanistic standpoint.
Magnesium and zinc also participate in bone and connective tissue metabolism and are reasonable accompaniments to silicon supplementation for structural support goals.
Form and Timing Effects
Orthosilicic acid (OSA) and its stabilised forms (choline-stabilised OSA, or ch-OSA) are the most bioavailable silicon supplement forms studied in clinical research. A randomised trial using ch-OSA found measurable increases in urinary silicon excretion, confirming meaningful absorption, and noted positive effects on hair tensile strength and nail brittleness over a 20-week period (Barel et al., 2005).
Silicon from colloidal silica, bamboo extract or horsetail extract is also found in supplements. Horsetail (Equisetum arvense) is a traditional source rich in silicon, though bioavailability from plant-bound silicon is generally lower than from orthosilicic acid forms.
Timing relative to meals has not been studied as rigorously for silicon as for other minerals. Taking silicon supplements with food is generally advisable to reduce any risk of gastrointestinal discomfort, though it does not appear to impair absorption.
Food Pairings
Silica-rich mineral waters and beer are the most bioavailable dietary silicon sources documented in research (Jugdaohsingh et al., 2000). If you prefer a whole-food approach, regular consumption of these sources provides meaningful silicon. Whole grains also contain silicon, but in a plant-fibre-bound form with lower bioaccessibility.
High-aluminium intake may interfere with silicon metabolism; silicon and aluminium are believed to form insoluble complexes in the gut. This is a minor concern for most people with typical dietary patterns.
Practical Tips
- Choose an orthosilicic acid or choline-stabilised OSA supplement for the best bioavailability.
- Take with food to minimise any gut discomfort and maintain steady absorption.
- Combine with vitamin C from food or supplements if your goal includes connective tissue or skin support.
- Be patient: effects on connective tissue structure are slow to develop; consistent supplementation over months is needed to assess outcomes.
- Consider dietary sources such as mineral water naturally high in silica as a complement to supplementation.
For joint and connective tissue support products available at maxfit.ee, browse the joints and cartilage section.
FAQ
Is silicon dioxide in supplements the same as bioavailable silicon?
No. Silicon dioxide used as a flow agent in tablets and capsules is largely biologically inert. Look for orthosilicic acid or choline-stabilised OSA as the active form.
Can I get enough silicon from diet alone?
Many people do get adequate dietary silicon from wholegrains, vegetables and water. Those seeking silicon for connective tissue support at meaningful levels may prefer a standardised supplement with known bioavailability.
How long does silicon take to show effects on hair, skin or nails?
The clinical trial that showed improvements in hair tensile strength and nail brittleness used 20 weeks of supplementation before measuring outcomes (Barel et al., 2005), which gives a realistic timeframe for structural effects.
References
Jugdaohsingh, R., Anderson, S. H. C., Tucker, K. L., Elliott, H., Kiel, D. P., Thompson, R. P. H., & Powell, J. J. (2000). Dietary silicon intake and absorption. American Journal of Clinical Nutrition, 75(5), 887-893.
Barel, A., Calomme, M., Timchenko, A., De Paepe, K., Demeester, N., Rogiers, V., Clarys, P., & Vanden Berghe, D. (2005). Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin. Archives of Dermatological Research, 297(4), 147-153. https://pubmed.ncbi.nlm.nih.gov/16205932/
