Silicon is the second most abundant mineral on Earth after oxygen and is found in most foods and even in drinking water. It is necessary for bone health because of its role in collagen synthesis, but it can also improve skin and hair health. (1,2) Although there are forms of silicon that can be harmful if inhaled, silicon from food and supplements shouldn't cause any problems in the everyday amounts that people consume. (3,4)  

How much silicon do we need? 

The health effects of silicon have not yet been fully unearthed, so there is currently no official daily intake. Studies so far suggest that the healthy range is quite wide, as excess is easily eliminated when the kidneys are functioning properly. For example, silica used as an additive has been found to be safe up to 1500 mg per day, which is several times the normal intake. (4) 

The average daily intake of silicon is between 20-50 mg in Western countries, while in areas with a predominantly plant-based diet it can be as high as 200 mg per day. (5,6) To enjoy its health benefits, it is recommended to consume at least 25 mg. (1) 

Different types of silicon 

Plants need large amounts of silicon to grow, making plant foods, including cereals, the best sources of silicon. Of animal foods, however, only shellfish contain significant amounts. (5) 

Dissolved forms of silicon are also found in drinking water and in even greater amounts in beer, to the extent that in some countries, the latter accounts for the majority of daily silicon intake by adults. (5) 

Silicon dioxide is a popular additive found in many foods and medicines. This is the same form that is found in natural foods - all of which have been found to be safe in studies to date.  

Various forms of silicon, such as silicon from bamboo or the field horsetail, are also commonly found in multivitamins and other dietary supplements on account of their beneficial effects on skin, hair, and bone health. 

Effects of silicon on skin and hair 

Silicon is necessary for collagen synthesis, and consequently for maintaining healthy skin and hair. Consequently, its deficiency may contribute to hair thinning and the development of wrinkles.  

Silicon supplementation has been tested in several studies to see if it can improve skin and hair condition. In a randomized controlled trial in 2007, a well-absorbed form of 10 mg of silicon per day successfully slowed hair thinning and hair breakage in susceptible participants. (7) 

A randomized trial in 2005 also tested the supplementation of 10 mg of silicon per day, observing its effects on hair condition and, in particular, skin. Silicon supplementation was effective in improving skin condition according to the parameters tested and moreover, had a positive effect on both hair and nails of the participants. 

The effects of silicon on bones 

Decades ago, it was observed that silicon deficiency led to various abnormalities in the skeleton of animals and significantly slowed their growth. Silicon supplementation, however, was capable of lifting these issues and increasing bone density in animals. (1)  

Studies have shown that people with the highest intakes of silicon have much stronger bone mass than those who consume little. (9) 

There have been other promising results on silicon supplementation. In a randomized trial, it boosted levels of a special type of collagen responsible for the formation of new bone material, which may reduce the risk of bone fractures. In other studies, it has also successfully increased bone density. (10, 11) 

Researchers suggest that to achieve the desired effect, a minimum daily intake of 25 mg of silicon should be aimed for, or at least 5-10 mg in more absorbable forms consumed as a supplement. 

Interesting facts 

Certain forms of silicon can be particularly dangerous if inhaled. The most harmful is the now-banned asbestos, which was once widely used because of its beneficial properties, but as it turns out, over time fine particles can flake off and cause very serious lung damage. Silica dust, which is found in many materials used in the construction industry, is also a powerful inflammatory agent when inhaled and it is important to guard against it. (3) Additives containing silica nanoparticles have also been suspected of having adverse health effects. They are currently under investigation, but to date, it has not been demonstrated that they are harmful in average quantities. (4,12) 

[The cover image of the note shows the mineral form of silicon.]