Horsetail, Equisetum arvense, herb and extracts are the most concentrated sources of silica for dietary supplements. Many foods also contain silica including alfalfa sprouts, beets, brown rice, bell peppers, soybeans, leafy green vegetables, root vegetables, cooked dried beans and peas, and whole grain breads and cereals. Silicon is also sold as trace silicic acid and sodium metasilicate.
Standardized silica capsules, tablets and liquid supplements; multivitamin pills containing silica.
Immune System Health
Lower Back Pain
Mineral Deficiency (RDI=5-20mg/day)
Silicon is the second most abundant element of the earth’s crust (26%), second only to oxygen in abundance (49%). Silica, also known as silicon dioxide, is a compound made out of the two most abundant elements in the Earth’s crust, silicon and oxygen (SiO2). Silicon is not found free in nature but occurs chiefly as silica. Silicon is important to plant and animal life. Silicon was recognized as an essential trace element is 1972. In the human body, silicon is found in the connective tissues, tendons, ligaments, cartilage, and blood vessels and it is thought that the mineral is essential for their integrity. Silicon is also required for healthy nails, skin and hair and for calcium absorption in the early stages of bone formation. Studies have shown that the amount of silicon in arteries starts to decline as atherosclerosis starts to develop. French research suggests that silicon can help to prevent osteoporosis and can be used to treat bone fractures. Aging and low estrogen levels reputedly decrease the body’s ability to absorb silicon. A human fetus has an abundant supply of silicon in many tissues. Collagen, a primary component of connective tissue and a third of all body protein, is rich in silicon. Elastin is also rich in silicon. Silica, in close cooperation with vitamin C, has the ability of holding moisture in tissues through compounds known as mucopolysaccharides. Also known as glycosaminoglycanes, these mucilaginous carbohydrates together with collagen and elastin make up our connective tissues. Silica is also vital for tooth structures. It is involved in the hardening of enamel, prevents bleeding gums and recession (a cause of loose teeth) which ultimately can prevent the need for dentures. Horsetail is among the riches plant sources of silicon in the form of monosilicic acid, which the body can readily use.
Silica, also known as silicon dioxide, is a compound made out of the two most abundant elements in the Earth’s crust, silicon and oxygen (SiO2). Silica has three main crystalline varieties: quartz (by far the most abundant), tridymite, and cristobalite. Silica is the main constituent of more than 95 percent of rocks that comprise 59 percent of the earth’s crust. Quartz makes up about 12 percent of the land surface and about 20 percent of the Earth’s crust. The highest levels of silicon in humans are found in the skin and connective tissues. Blood averages about 0.5 milligrams of silicon per liter of blood plasma and amounts in the liver, heart and lungs range from 2 to 10 milligrams per kilogram. Silica from spring horsetail, Equisetum arvense, is much more highly bio-available than purely mineral sources of silica due to the presence of flavonoids and other cofactors in the extract, which enhance silica’s uptake. Increased bioavailability can be assured through naturally chelated supplements. Natural chelates present in organic vegetal silica assist in successfully absorbing silica through intestinal walls into the bloodstream and from there into the tissues. Successful supplementation can be ensured if silica is extracted from natural horsetail herb, such as Flora-Sil, carefully extracted from springtime horsetail herb using an aqueous extraction method that eliminates horsetail’s abrasive quality. Note: The silica content of foods is usually found in the skin or other outer layers of a food (i.e. rice polishing) and thus silica is often the first to go in food processing. The current intake of silica by the average person is suspected to be low.
There is currently no established RDA for silica. The recommended daily intake for silica varies greatly between authors. Most authoritative sources recommend that the daily intake should be between 5-20mg daily. Other sources recommend taking between 22-33mg of silica daily obtained from spring horsetail extracts that provide naturally chelated silica. Studies do show marked improvement in bone mending and skin health at this level. Other sources recommend much higher intakes (based on traditional diets) ranging between 100-1000mg daily, although these high levels may not be necessary to obtain the health benefits of silica – and safety above 50mg daily has not been established and so should not be recommended. Silica-rich horsetail herb and extracts can also be made into a poultice for stimulating and accelerating wound healing, as a hair rinse and as a skin conditioner. Silica’s greatest benefits come from internal use with a proper formula.
Brown, M.1990. Present Knowledge in Nutrition, 6th edition. International Life Sciences Institute, Nutrition Foundation. Washington, DC, Pp. 301-302
Duke, J. 1997: The Green Pharmacy, The Ultimate Compendium of Natural Remedies from the World’s Foremost Authority on Healing and Herbs. Pp. 37; 132-133; 414-415. Rodale Press.
Graefe EU, Veit M. 1999. Urinary metabolites of flavonoids and hydroxycinnamic acids in humans after application of a crude extract from Equisetum arvense. Phytomedicine 1999 Oct; 6(4): 239-46.
Piekos R, Paslawska S, Grinczelis W. 1976. Studies on the optimum conditions of extraction of silicon species from plants with water. III. On the stability of silicon species in extracts from Equisetum arvense herb. Planta Med. 1976 Jun; 29(4): 351-6.
Piekos R, Paslawska S. 1975. Studies on the optimum conditions of extraction of silicon species from plants with water. I. Equisetum arvense L. Herb. Planta Med. 1975 Mar; 27(2): 145-50.