Although not considered an essential nutrient from a biological or nutritional standpoint, silicon’s abundance in nature and importance in human health cannot be disputed. Following oxygen, silicon is the second most plentiful element on earth. This mineral is the number one mineral found in the earth’s crust. Silicon’s active form is expressed as Si02, often used to make many external items that humans use for everyday tasks (e.g. glass). Silicon is present in two separate compounds that assist and aid the body in specific tissue processes. It represents nearly 0.5 percent of our entire body weight.
Protein compounds rely on the forms of silanate or silicic acid to support crucial connective tissue structures located throughout the body. The most important being located in the aorta, trachea, bone, and the largest organ of our body, the skin. Silicon is vital in providing strength and stability to these regions. Extensive research on silicon exists, labeling silicon as a ‘critical’ macro mineral. The nutrients boron, calcium, magnesium, manganese, and potassium are needed for optimum utilization of this mineral in our bodies. 
* It is very important to note that many individuals confuse the nutrient/element silicon, with silicone. While silicon is a natural occurring substance in nature, the latter (silicone) is made by man using controversial polymers that are popular in the industrial workplace. Most notably, these industrial polymers are used for breast enhancements and enlargements for women seeking aesthetic improvement. *
A food graph for this particular mineral is omitted. This is due to silicon’s abundance in a wide variety of foods; plant sources represent the best sources of silicon in diet, while animal and other products do not. Refining, processing, and preparation are determinants of silicon intake and absorption in human diet.
The richest sources of silicon are usually represented by an unrefined product and the amount of fiber it contains. Dietary sources such as unrefined grains (wheat, oat, millet, barley, etc.), cereal products, onions, and leafy green vegetables provide the highest concentrations of silicon. The pectin in various fruits also provides the substance alginic acid, which contains minute amounts of this trace mineral. Water may also be a beneficial source. 
Silicon’s use in humans is still widely speculated by science and continues to undergo trial. The majority of its use is through herbal remedies that promote beauty and health of the hair, skin, and nails. This is in direct correlation to silicon’s ability to produce the protein collagen. Collagen is responsible for a variety of processes including the strength and rigidity of not only the hair, skin, and nails, but is also critical in bone flexibility, cell membrane processes, and tendon and ligament health.
Silicon may also be of great importance in the formation and maintenance of bone health. Silicon is found is areas of calcification. These areas include our skeletal structure, teeth, and even in the chondroitin sulfates of cartilage. Realizing this, researchers have used both silica and silicon in nutritional supplementation to reduce the risks and symptoms of certain joint conditions, namely atherosclerosis and osteoporosis.
Another area of ongoing study is silica and silicon supplementation and how this type of nutritional approach effects the majority of biochemical processes in differing human systems. Of increased concern is our immune system and its effectiveness to decrease the risks of developing certain conditions, especially the common cold. [3, 4, 5, 6]
There has been no established Recommended Dietary Allowance (RDA) for this trace mineral. Requirement of silicon from dietary sources remains quite small, ranging from 2 to 5 milligrams per day. However, the bioavailability of silica and silicon varies in relation to diet and the food sources that are chosen for intake. Thus, the average dietary intake for this macro mineral ranges from 1 to 1.5 milligrams daily. Interestingly, adverse effects have not been reported from dosages exceeding 40 milligrams per day.
Additional dosages can be achieved by eating more whole grain and vegetables sources, or by taking herbal supplementation in the form of capsules, tablets, or liquid drops.
A deficiency in silicon has never been clinically studied in a human subject. Research on animals, however, leads many scientists to believe that a silicon deficiency in humans may lead to a variety of irregularities. These include decreased bone and deficient bone and tooth structures, and increased development rates of atherosclerosis and heart disease. Physical endurance and stamina may also be directly impeded by the inadequate intake of silicon.
The majority of silicon-containing compounds are considered non-hazardous. One major example is the many over-the-counter antacids , mainly those containing magnesium triscilate and other silicon compounds. These sulfur-based compounds, throughout their origin with excessive human consumption, have failed to produce any adverse affects in present and previous decades.
1. Chapuy MC, et al. Prevention and Treatment of Osteoporosis. Aging (Milano). Aug 1995;7(4): 164-73.
2. Dietary Reference Intakes Tables â€“ Additional Information. Arsenic, Boron, Calcium, Chromium, Copper, Flouride, Iodine, Iron, Magnesium, Manganese, Molybdenum, Nickel, Phosphorus, Selenium, Silicon, Vanadium, and Zinc.
http://www.iom.edu/subpage.asp?id=7292 â€“ Text
3. Eisinger J, et al. Effects of Silicon, Flouride, Etidronate and Magnesium on Bone Mineral Density: A Retrospective Study. Magnes Res. Sep 1993;6(3):247-49.
4. Nielsen, F.H. (1999) Other trace elements. In: Modern Nutrition in Health and Disease (Shils M. E., Olson J.A., Shike, M. & Ross, C. A. eds.), 9th ed.,pp. 283-304. Williams & Wilkins, Baltimore, MD.
5. Seaborn, C.D. & Nielsen, F.H. (1993) Silicon: A nutritional beneficence for bones, brains and blood vessels? Nutr. Today 28: 13-18.
6. Schiano A, et al. Silicon, Bone Tissue Immunity. Rev Rhum Mal Osteoartic. Sep 1979;46(7-9): 483-86.