Silicon Deficiency: What the Evidence Shows

Here is the honest bottom line, stated up front: there is no recognized silicon deficiency syndrome in humans. Silicon is the second most abundant element in the Earth's crust, it is present in essentially every diet, and no doctor diagnoses, no lab test screens for, and no medical textbook describes a disease caused by "low silicon" in people. That is very different from saying silicon does nothing. In chicks and rats raised on artificial silicon-free diets, a genuine deficiency stunts growth and disrupts bone and connective tissue — which is why silicon is sometimes called a "beneficial" or "possibly essential" trace element. And in people, several large population studies have found that those who eat more silicon tend to have somewhat denser bones, a real and interesting finding. But an association in a survey is not the same as a deficiency disease, and the human supplement trials so far are small and preliminary. This page lays out exactly what the evidence does and does not show, why a true shortfall is essentially never seen in everyday life, the rare and theoretical edge cases, and the low-key practical takeaway — which, for almost everyone, is simply to eat normally.

Table of Contents

1. What the Evidence Actually Says
2. The Biology: Why a Human Shortfall Isn't Seen
3. The Bone and Connective-Tissue Research, Honestly
4. Who, If Anyone, Could Run Low
5. What to Do (Spoiler: Not Much)
6. Related Nutrients and Minerals
7. When to Talk to a Doctor
8. Key Research Papers
9. Connections
10. Featured Videos

What the Evidence Actually Says

It is worth being precise about words. A deficiency, in the strict nutritional sense, means that going without a nutrient produces a recognizable disease that the nutrient then cures — the way too little vitamin C causes scurvy, or too little iodine causes goiter. By that standard, silicon has never met the bar in humans. No silicon-deficiency illness has ever been described in a person, no clinical guideline defines a "low silicon" threshold, and routine lab panels do not measure it. The U.S. Institute of Medicine has not set a Recommended Dietary Allowance (RDA) for silicon precisely because the evidence is not strong enough to prove it is essential or to define how much a person needs.

So why does silicon come up at all in discussions of bone and connective-tissue health? Because the picture is genuinely more interesting than "irrelevant." The honest summary breaks into three tiers of evidence:

• Strong evidence — in animals only. When chicks and rats are raised on highly purified, silicon-stripped laboratory diets, they grow poorly and develop abnormalities of bone, cartilage, and connective tissue. Edith Carlisle's chick experiments and Klaus Schwarz and David Milne's rat experiments, both published in 1972, are the foundation of the entire field. These are real, reproducible deficiency states — but they require an artificial diet that does not exist in nature or in any human kitchen.
• Moderate evidence — population associations in people. Large dietary surveys have repeatedly found that people who happen to eat more silicon tend to have higher bone mineral density. The most cited is the Framingham Offspring study (over 2,800 people), where higher silicon intake tracked with denser hip bone — an effect seen most clearly in men and younger women. This is a real signal, but it is observational: people who eat more silicon also tend to eat more whole grains, fruits, vegetables, and beer, and to differ in many other ways, so the silicon itself may not be the cause.
• Weak / preliminary evidence — human supplement trials. Only a handful of small trials have given people a silicon supplement (usually a form called choline-stabilized orthosilicic acid) and measured bone. They are promising at the level of laboratory markers but are too small and too few to prove that silicon prevents fractures or treats osteoporosis. No major health authority recommends silicon supplements for bone health on the basis of this evidence.

Putting it plainly: silicon looks beneficial and may even be conditionally important, but a clinically meaningful deficiency in free-living people has simply never been demonstrated. It is correct, and not a dodge, to say this is not a clinical problem you need to watch for.

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The Biology: Why a Human Shortfall Isn't Seen

Two facts about silicon's chemistry and our diet explain why no one runs low in ordinary life.

First, silicon is everywhere. Silicon (chemical symbol Si) makes up roughly a quarter of the Earth's crust by weight — it is the main ingredient of sand, quartz, and most rock. Plants pull it out of the soil as they grow, so it ends up in the parts of plants we eat. The body absorbs it not as the rock-hard mineral but as a small, water-soluble molecule called orthosilicic acid (Si(OH)₄), which dissolves readily in water and other beverages. Because plants concentrate it and water carries it, a normal mixed diet delivers silicon continuously without anyone trying. Typical Western intakes fall somewhere around 20–50 milligrams a day, with the richest contributors being whole grains and grain products (oats, barley, bran, brown rice), some fruits and vegetables (especially green beans and bananas), and — perhaps surprisingly — beer, in which barley husks leach highly absorbable silicon into the brew. Drinking water and some mineral waters add more.

Second, the body is forgiving about it. Orthosilicic acid is absorbed easily in the gut, circulates in the blood, and any excess is filtered out efficiently by the kidneys and passed in the urine. There is no large dedicated storage organ for silicon and no tight hormonal control system the way there is for calcium or potassium — intake in roughly equals excretion out, day to day. A balance study by Pruksa and colleagues confirmed exactly this in human volunteers: what people take in is closely matched by what they excrete. The practical consequence is that you cannot easily "deplete" yourself of silicon by eating a normal varied diet, because you are topping it up with every meal and drink.

Contrast this with a true essential nutrient that humans can run short of. Vitamin C is not made by the body and is destroyed by cooking, so a diet truly devoid of fresh produce causes scurvy within weeks. Iron is poorly absorbed and easily lost through bleeding, so deficiency is common worldwide. Silicon is the opposite story: abundant in food, well absorbed, freely excreted, and not depleted by everyday eating. That combination is why a deficiency state, easy to create artificially in a lab animal on a purified diet, essentially never arises in a person living a normal life.

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The Bone and Connective-Tissue Research, Honestly

This is the area where silicon earns its reputation, so it deserves a careful, non-hyped walk-through. The interest is biologically reasonable: silicon shows up in the body wherever connective tissue is being built — in growing bone, in cartilage, in the walls of arteries, and in the "scaffolding" proteins like collagen that hold tissues together. The open question has always been whether that presence is doing real work, or is just a passenger.

What the laboratory shows. In a dish, orthosilicic acid nudges human bone-forming cells (osteoblasts) to make more type-1 collagen, the main protein framework that bone mineral later hardens onto. Reffitt and colleagues demonstrated this collagen-stimulating effect directly in human bone-like cells. A useful analogy: collagen is the rebar and concrete forms of a building, and calcium and phosphate are the concrete poured in. Silicon, in these experiments, seems to help lay down a better framework — which would matter for bone quality, not just bone density. This is a plausible mechanism, but cell-dish findings do not automatically translate to whole people.

What the population studies show. Several large observational studies have linked higher dietary silicon to higher bone mineral density. In the Framingham Offspring Cohort, Jugdaohsingh and colleagues found that people in the highest silicon-intake group had meaningfully greater hip bone density than those in the lowest — an association strongest in men and pre-menopausal women, and noticeably weaker in post-menopausal women. The Aberdeen Prospective Osteoporosis Screening Study (APOSS) by Macdonald and colleagues added an important nuance: silicon's apparent benefit seemed to depend on estrogen status, showing up mainly in women who had adequate estrogen (pre-menopausal, or post-menopausal women on hormone therapy). That estrogen interaction is a clue that silicon, if it helps, helps as part of a larger system rather than as a stand-alone fix.

Why associations are not proof. Here is the honesty this topic requires. People who eat more silicon are not a random group. They tend to eat more whole grains, more produce, and more beer — foods and drinks that travel with many other nutrients (magnesium, potassium, fiber, polyphenols) and with whole lifestyle patterns that independently affect bone. Statisticians call the silicon signal potentially confounded: the denser bones might be caused by the overall healthier dietary pattern, with silicon merely along for the ride as a marker of eating more plants. Observational studies can adjust for some of this, but they can never fully untangle it. That is exactly why a correlation, however consistent, cannot establish that silicon itself prevents bone loss.

What the human trials show — and don't. The cleanest test is a randomized trial: give some people silicon and others a placebo, then measure what happens. Very few exist. The most cited is Spector and colleagues' 2008 trial, in which osteopenic women received choline-stabilized orthosilicic acid (a well-absorbed supplement form) plus calcium and vitamin D, versus calcium and vitamin D alone. The silicon group showed favorable movement in a marker of bone formation and a hint of benefit at the femur, but the study was small and measured biochemical signals more than hard outcomes like fractures. No large trial has shown that silicon supplements prevent fractures or treat osteoporosis, and that is the outcome that would matter. The careful reviews in this field — Price's 2013 review and the Sripanyakorn group's overview of dietary silicon and bone — reach the same measured conclusion: silicon is a promising area for bone health that is biologically interesting and worth more research, but the human evidence is not yet strong enough to call it a treatment, let alone to define a deficiency.

So the fair verdict is a "maybe, partly, for bone quality, as part of a good diet" — not "low silicon causes weak bones." For the established, well-proven players in bone health, see Calcium, Magnesium, and the dedicated page on Bone Loss and Osteoporosis.

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Who, If Anyone, Could Run Low

If a true silicon shortfall basically never happens in everyday life, the reasonable question is whether any situation could produce one. The honest answer is: only narrow, mostly theoretical cases — and even for these, there is no established disease and no recommendation to test or treat.

• Long-term total parenteral nutrition (TPN). The clearest candidate is someone fed entirely by vein for a long time because their gut cannot be used. Because intravenous nutrition is a manufactured formula, the silicon content can be low and is not deliberately added. In principle this is the one setting where intake could fall far below what a normal diet provides. Even here, however, there is no defined silicon-deficiency syndrome described in TPN patients, and clinical nutrition guidelines do not list silicon among the trace elements that must be supplemented — unlike zinc, copper, selenium, or chromium, which genuinely are added to long-term formulas. (Of note, the more documented silicon concern in this population is the opposite problem — trace contaminants in IV fluids — which belongs on the Silicon Toxicity page, not here.)
• Very restrictive or highly processed diets. Diets stripped of whole grains, produce, and unprocessed foods deliver less silicon, because refining grains removes the silicon-rich outer husk and bran. A person living mostly on heavily refined, low-fiber food would take in less silicon — but they would also be short of fiber, magnesium, potassium, and many vitamins, and it is those well-established shortfalls, not silicon, that would matter clinically. The fix (eat more whole, plant-based food) is the same either way.
• Aging, in theory. Some researchers have speculated that the body's ability to use silicon may decline with age, and that this could play a small part in why bones and connective tissue weaken over the years. This is a hypothesis raised to explain why silicon's bone association looks weaker in post-menopausal women — it is not an established deficiency and not a reason to supplement.

Notice what is not on this list: there is no genetic silicon-deficiency disorder, no malabsorption syndrome built around silicon, and no recognized clinical picture you could point a doctor to. That absence is itself the most important piece of evidence.

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What to Do (Spoiler: Not Much)

Because there is no deficiency to correct, the practical advice here is refreshingly low-key. For the overwhelming majority of people, the right amount of effort to put into "getting enough silicon" is essentially none — a normal varied diet has it covered.

If you would like to favor silicon-rich foods anyway, the good news is that they are exactly the foods already recommended for general and bone health, so you lose nothing by leaning into them:

• Whole grains — oats, barley, brown rice, bran, and whole-grain bread are the single biggest dietary source, because silicon concentrates in the bran and husk that refining removes.
• Certain fruits and vegetables — green beans, bananas, and other plant foods contribute steadily. Leafy greens and root vegetables add smaller amounts across the day.
• Beverages — beer is unusually high in well-absorbed silicon (from the barley), and some mineral waters and drinking waters contribute a meaningful share. This is a point of interest, not a health endorsement: any benefit of beer's silicon is far outweighed by the well-established harms of alcohol, so beer is not a recommended "silicon source."

On supplements: silicon supplements exist — choline-stabilized orthosilicic acid (the form used in the research), plus older preparations like silica gel and horsetail-plant extracts. The honest position is that there is no proven reason for the general public to take them. The human evidence for benefit is preliminary, no deficiency is being corrected, and the foods that supply silicon are cheap, pleasant, and good for you for many other reasons. People sometimes try silicon supplements hoping for stronger hair, skin, and nails; the evidence there is similarly thin and is discussed on the Silicon for Hair and Nails page. If you are concerned about bone health, your time and money are far better spent on the proven essentials — adequate calcium, vitamin D, protein, weight-bearing exercise, and not smoking — than on silicon.

One caution worth flagging: horsetail, an herb marketed as a "natural silicon" source, contains an enzyme (thiaminase) that can break down vitamin B1 (thiamine), and products vary widely in quality and purity. That is another reason food, not herbal supplements, is the sensible way to get silicon.

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Related Nutrients and Minerals

Silicon does not act alone, and several of the minerals it is grouped with are far better established — which helps put silicon in perspective.

• Calcium and Phosphorus are the actual building blocks of bone mineral — the "concrete." If silicon helps at all, it is by improving the collagen framework that calcium and phosphate harden onto, not by replacing them. Real, common deficiencies of these (and of vitamin D, which governs calcium absorption) are what genuinely threaten bone.
• Magnesium is essential, frequently low in real diets, and important for bone and hundreds of other processes — a far higher-priority mineral to get right than silicon.
• Boron is, like silicon, a "possibly beneficial" ultra-trace element studied for bone, with similarly modest and preliminary human evidence — a useful comparison, since both occupy the same honest gray zone between "essential" and "irrelevant."
• Manganese and Zinc are genuine essential trace minerals involved in connective-tissue and bone enzymes; unlike silicon, true deficiencies of these are recognized clinical entities with defined consequences.
• Vitamin C and collagen connect to silicon through the collagen story: vitamin C is required to build collagen, collagen is the protein silicon appears to influence, and all three are part of how the body maintains connective tissue. Vitamin C deficiency (scurvy) is a real, dramatic illustration of what a true connective-tissue nutrient shortfall looks like — a striking contrast to silicon, where no such picture exists.

For the full picture of silicon's possible roles, see the Silicon overview and its benefits pages on bone density and connective tissue.

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When to Talk to a Doctor

Because silicon deficiency is not a real clinical condition, there are no silicon-deficiency symptoms to watch for and no reason to ask for a silicon blood test — such testing is not part of standard care and would not guide any treatment. What follows are the situations where the underlying concern people bring to silicon — usually bones, joints, hair, skin, or nails — genuinely warrants a conversation with a clinician:

• Concern about bone thinning or osteoporosis — especially after age 50, after menopause, after a fracture from a minor fall, with long-term steroid use, or with a family history. The right step is a bone-density (DEXA) scan and attention to the proven essentials, not silicon. See Bone Loss and Osteoporosis and Osteoporosis.
• Sudden, marked changes in hair, skin, or nails — significant hair loss, very brittle or spooned nails, or notable skin changes can signal real, treatable issues such as thyroid disease, iron deficiency, or other nutritional gaps. These deserve a proper work-up rather than a silicon supplement.
• Before starting any silicon-containing supplement — particularly horsetail-based products, which can interfere with thiamine (vitamin B1) and vary in purity, and especially if you are pregnant, breastfeeding, take other medications, or have kidney disease.
• You are fed long-term by vein (TPN) — trace-element needs in this setting are real and are managed by a clinical nutrition team. They will supplement the trace minerals that genuinely require it; silicon is not currently among them, but your team is the right source of guidance.

The unifying message: if something feels wrong with your bones, joints, or connective tissue, that is worth a doctor's attention — but the answer almost certainly lies with well-established nutrients and conditions, not with a silicon shortage.

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Key Research Papers

1. Carlisle EM (1972). Silicon: An Essential Element for the Chick. Science;178(4061):619-621. — DOI: 10.1126/science.178.4061.619
2. Schwarz K, Milne DB (1972). Growth-promoting Effects of Silicon in Rats. Nature;239(5371):333-334. — DOI: 10.1038/239333a0
3. Jugdaohsingh R, Tucker KL, Qiao N, Cupples LA, Kiel DP, Powell JJ (2004). Dietary Silicon Intake Is Positively Associated With Bone Mineral Density in Men and Premenopausal Women of the Framingham Offspring Cohort. Journal of Bone and Mineral Research;19(2):297-307. — DOI: 10.1359/jbmr.0301225
4. Macdonald HM, Hardcastle AC, Jugdaohsingh R, Fraser WD, Reid DM, Powell JJ (2012). Dietary silicon interacts with oestrogen to influence bone health: Evidence from the Aberdeen Prospective Osteoporosis Screening Study. Bone;50(3):681-687. — DOI: 10.1016/j.bone.2011.11.020
5. Spector TD, Calomme MR, Anderson SH, Clement G, Bevan L, et al. (2008). 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;9:85. — DOI: 10.1186/1471-2474-9-85
6. Reffitt DM, Ogston N, Jugdaohsingh R, Cheung HFJ, Evans BAJ, et al. (2003). Orthosilicic acid stimulates collagen type 1 synthesis and osteoblastic differentiation in human osteoblast-like cells in vitro. Bone;32(2):127-135. — DOI: 10.1016/s8756-3282(02)00950-x
7. Jugdaohsingh R, Anderson SHC, Tucker KL, Elliott H, Kiel DP, et al. (2002). Dietary silicon intake and absorption. The American Journal of Clinical Nutrition;75(5):887-893. — DOI: 10.1093/ajcn/75.5.887
8. Sripanyakorn S, Jugdaohsingh R, Elliott H, Walker C, Mehta P, et al. (2004). The silicon content of beer and its bioavailability in healthy volunteers. British Journal of Nutrition;91(3):403-409. — DOI: 10.1079/bjn20031082
9. Sripanyakorn S, Jugdaohsingh R, Thompson RPH, Powell JJ (2005). Dietary silicon and bone health. Nutrition Bulletin;30(3):222-230. — DOI: 10.1111/j.1467-3010.2005.00507.x
10. Pruksa S, Siripinyanond A, Powell JJ, Jugdaohsingh R (2014). Silicon balance in human volunteers; a pilot study to establish the variance in silicon excretion versus intake. Nutrition & Metabolism;11:4. — DOI: 10.1186/1743-7075-11-4
11. Price CT, Koval KJ, Langford JR (2013). Silicon: A Review of Its Potential Role in the Prevention and Treatment of Postmenopausal Osteoporosis. International Journal of Endocrinology;2013:316783. — DOI: 10.1155/2013/316783

PubMed Topic Searches

• PubMed — Silicon as an essential trace element in human nutrition
• PubMed — Dietary silicon intake and bone mineral density
• PubMed — Orthosilicic acid, collagen, and bone formation
• PubMed — Silicon bioavailability and dietary absorption
• PubMed — Choline-stabilized orthosilicic acid supplementation

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Connections

• Silicon Overview
• Silicon Toxicity
• Silicon Benefits Hub
• Silicon and Bone Density
• Silicon and Connective Tissue
• Silicon for Hair and Nails
• Calcium
• Bone Loss and Osteoporosis
• Magnesium
• Phosphorus
• Boron
• Manganese
• Zinc
• Vitamin C
• Collagen
• Osteoporosis
• Comprehensive Metabolic Panel

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