Some people believe that taking silica supplements improves hair growth. However, the Mayo Clinic reports that taking nutritional supplements does not improve hair growth in individuals eating an already nutritious diet.
The typical diet supplies 1 gram of silica per day, and the recommended intake is 200 to 500 milligrams per day. Being deficient in silica causes brittle nails and hair, however silica is one of the most commonly found minerals on Earth. It is found in both water and in most foods, particularly those that are plant-based. Abundant silica is present in all but the most highly processed and limited diets. Most cases of silica deficiency were artificially created in the laboratory using test animals.