Bioavailability of silicon from food and food supplements

The bioavailability of silicon from three different silicon sources was stu died, A diet rich in silicon, a tablet containing a dry extract of horsetai l and a solution of silicon in a choline-glycerol matrix were compared. Blo od and urine of one healthy test person were sampled to monitor the silicon uptake. The silicon content of blood and serum samples was determined by g raphite furnace atomic absorption spectrometry. Strongly diverging results were obtained for the three different silicon sources. Neither an increase in urinary silicon excretion nor in serum silicon content was observed when feeding the silicon rich diet. Urinary silicon excretion did significantly (P < 0.05) rise during supplementation with tablets containing dry extract of horsetail. Intake of a solution of silicon in a choline-glycerol matrix resulted in a significantly (P < 0.05) increased urinary silicon excretion and serum silicon content. From these results it can be concluded that spe ciation (chemical form, matrix) strongly influences the bioavailability of silicon.