Selenium status in pregnant women of a rural population (Zaire) in relationship to iodine deficiency.

A combined deficiency of two essential trace elements--selenium and iodine--is presumed responsible for the significantly elevated frequency of myxoedematous cretinism in Central Africa. This condition is characterized by mental deficiency stunted growth and persistent hypothyroidism. To determine selenium and iodine status in Zaire a study was conducted among pregnant women attending prenatal clinics in 30 rural health centers throughout the country. The mean serum selenium level was similar to that in non-deficient areas (80-120 ng/ml) in Bas-Zaire marginally decreased (55-80 ng/ml) in the regions of Bandundu and Kasai and moderately decreased (under 55 ng/ml) in Kivu Haut-Zaire Equateur and Shaba. The frequency of abnormally low urinary iodine (under 5mcg/dl) ranged from 20% in Bas-Zaire to 84% in Haut-Zaire. Biochemical maternal hypothyroidism was present in every region except Bas-Zaire with frequencies ranging from 3% in Kivu to 12% in Equateur. There was a significant correlation between the mean levels of thyroid function parameters and of selenium status in the various villages. Combined iodine and selenium deficiencies affect Equateur Haut-Zaire and Kivu where endemic myxoedematous cretinism occurs but also Shaba where it has not been previously described. In Equateur and Haut-Zaire iodine deficiency should be regarded as a public health priority. Selenium deficiency on the other hand should not be considered a pressing public health concern.