Urinary excretion of silica in humans following oral administration of Magnesium Trisilicate

Summary and Conclusions

• 1. Five patients with peptic ulcer were studied as to urinary silica excretion (24 hours) on ulcer diets and were found to average 17.6 mg, SiO₂. A second group, three patients with pernicious anemia (achlorhydria) were found to average 27.06 mg. SiO₂.

• 2. During an experimental procedure in which each patient took 20 grams of magnesium trisilicate orally over a period of four days the increased excretion of urinary silica over the average daily excretion was 444.7 mg. for the first group and 593.7 mg. for the second group.

• 3. The individuals with pernicious anemia excreted more silica on regular diets and during the ingestion of magnesium trisilicate than the patients with peptic ulcer who had hydrochloric acid in their gastric secretion.

• 4. Silica absorption from the intestinal tract is probably dependent on the solubility of the silica in the alkaline intestinal contents.

• 5. The amount of silica absorbed appears to be related to the amount of silica present in intestinal contents.

• 6. A small proportion of the silica of magnesium trisilicate was absorbed and excreted in the urine of the patients studied.

• 7. None of the patients studied showed any evidence of toxicity from the administration of magnesium trisilicate.