Children with Down's syndrome have low levels of zinc, according to a recent study.
Zinc is involved in thyroid hormone production, and the Down's children had significantly lower plasma levels of zinc and zinc dependent thyroid hormones than others in the controlled study.
The cause of the low plasma zinc was unclear, but it was not due to nutritional deficiency. One possibility is decreased intestinal absorption.
When the Down's syndrome children were given dietary supplements that increased their plasma zinc levels into the normal range, their thyroid hormone levels returned to normal.
The study was first reported in The Lancet (4 July).