[Changes in urinary calcium and magnesium levels during supplementation with iodine and selenium]

The authors examined 31 children aged 10-13 years before and after 5-month administration of 100 micrograms iodine (as iodide 100 Merck) and 57 university students (age 18-23 years) divided into four groups. The control group of 15 students received placebo daily, 20 students took selenium (50 micrograms selenium Merck), 8 students iodine (100 micrograms iodide) and 14 students a combination of equal amounts of both elements. The authors investigated the calciuria, mangesiuria and calcium/creatinine ratio and magnesium/creatinine ratio. They found a significant drop of magnesiuria in school children after iodine intake, and in university students there was a significant drop of the magnesium/creatinine ratio in iodine and selenium treated groups as well as those who received a combination of both elements. In the latter group there was also a significant drop of the urinary calcium/creatinine ratio. The findings assembled in a relatively small group of children and students is considered preliminary. It suggests, however, the possible influence of supplementation with iodine and selenium in commonly used amounts on calcium and magnesium excretion. Changes in the control group may be due to seasonal influences.