Q. My nails are brittle, and my hair doesn’t shine as I would like. Would a silicon supplement add luster to my hair and improve my nails?
A. Even though silicon is the most abundant mineral on Earth, it was mostly ignored and considered nutritionally useless to humans until very recently. Research on silicon is still in the early stages.
Silicon can be found all around us. The richest dietary sources of silicon are whole grains, cereal products, and vegetables, but it is found generously in hard drinking water. Silicon is also found in the food additives frequently used as anti-caking or anti-foaming agents, but the silicon in food additives is hardly absorbed at all. Daily silicon intake in the U.S. ranges from approximately 20 to 50 milligrams, roughly 10 times the minimal amount thought to be needed.
The problem is that most silicon compounds are not absorbed well. Whether obtained from food or silicon supplements, absorption is typically as low as 3%. Orthosilic acid, which is formed by chemically affixing water to silicon dioxide with the help of stomach acid, is absorbed better. However, if one’s stomach acid were too low to aid the absorption of silicon, it would also be too low to promote the absorption of the many other minerals known to be important for healthy hair and nails. Orthosilic acid can also be found in some health-food stores.
The human body contains about 7 grams of silicon, most of which is found in connective tissue (such as blood vessels, tendons, bone, hair, nails, and skin) where it is assumed to play an important role in their structural integrity. There is no solid research on the use of silicon to improve hair and nails, but the idea is not far-fetched, since silicon is important in the formation of cartilage. The earliest observation of silicon deficiency was found in chickens that developed abnormal joints and had significantly less collagen in long bones when deprived of silicon.
It has been proposed that silicon deficiency in humans may lead to circulation problems such as hardening of the arteries. In animal research this process was limited through intravenous administration of silicon, but the research was conducted more than 50 years ago and needs to be repeated. In more recent research silicon has been found to accelerate the rate at which calcium and other minerals are deposited in bone. Silicon-deficient chickens have a reduced number of the bone-forming cells, regardless of vitamin D status.
Soluble silica may be the natural binder for dietary aluminum and prevent its accumulation in the body. This may be important in preventing Alzheimer’s disease, which has been associated with excessive aluminum exposure. A polymer form of silicon known as oligomeric silica reduced the absorption of aluminum by two-thirds when compared with control subjects, whereas ordinary silica had no effect.
A new paradigm for the determination of nutritional requirements is needed, one which includes consideration of the total health effects of nutrients and not just their roles in preventing deficiency symptoms. Silicon is one of several minerals that are candidates for the new term Apparent Beneficial Intake, to replace Recommended Daily Allowance. These nutrients have identifiable health benefits, even though deficiency symptoms in humans are not yet documented.
This article appears in July 25 • 2003.