Iodine deficiency correction

Now we will address the socio-economic consequences of iodine deficiency correction, 21 years after its beginning. We worked under the assumption that when the correction is early, i.e., before conception or... 

Iodine is essential in the mammalian diet to produce the thyroid hormone thyroxine deficiency in humans causes goitre. Collectively, deficiencies of iodine, iron, zinc and vitamin A in humans are thought to be at least as widespread and debilitating as calorie deficiencies (Welch and Graham, 1999). The main source of iodine in soils is oceanic salts rather than parent rock, and so deficiency is most widespread in areas remote from the sea (Fuge, 1996). In principle deficiency is easily corrected with dairy supplements. However in practice this is not always feasible. Addition of iodate to irrigation water has successfully corrected widespread iodine deficiency in parts of China where the usual methods of supplementation had failed (Cao et al., 1994 Jiang et al 1997). However there is not much information on the behaviour of iodine in soil and water systems. 

Zimmermann MB Iodine requirements and the risks and benefits of correcting iodine deficiency in populations. J Trace Elem Med Biol 2008 22 81. 

Laminaria angusta Kjellim. L. cichorioides Miyabe. L. japonica Aresch. L. longipedalis Okam. L. religiosa Miyabe. Kun Bu or Hai Dai (thallus) Iodine, potasium, calcium, amino acids, laminarin, laminine, algin.33 Improve thyroid function, correct the malignant vicious cycle effect of iodine deficiency, lower blood pressure. 

Delange F. Correction of iodine deficiency benefits and possible side effects. Eur J Endocrinol 1995 132(5) 542-3. 

Delange F, de Benoist B, Alnwick D. Risks of iodine-induced hyperthyroidism after correction of iodine deficiency by iodized salt. Thyroid 1999 9(6) 545-56. 

Thyroid disorders may be divided into over- and underproduction of the thyroid hormones. These may be caused by thyroid gland disorders or disorders of the pituitary gland (TSH production) or hypothalamus (thyrotropin-releasing hormone release). Thyroid hormone deficiency in infancy may cause mental retardation if it is not corrected immediately after birth. For this reason, many states require thyroid function tests in all newborns. In adults, thyroid deficiency may be caused by Hashimoto s thyroiditis, an immune disorder, or dietary iodine deficiency, in which case it is called simple goiter. The term "myxedema" has been used to refer to hypothyroidism of whatever cause. Myxedemas may... 

Synergistic interactions occur in other tissues and can have important biological and clinical consequences. For example, die interaction between selenium and iodine has been investigated.It is known that deiodinases are selenoproteins and that they remove iodine from T4 to produce the biologically active T3. Also the selenoprotein glutathione peroxidase is active in the thyroid in the destruction of excess hydrogen peroxide and is therefore important in thyroid hormone production. In certain areas of the world, combined selenium and iodine deficiency can occur and affect treatment provision of selenium maybe necessary to correct hypothyroidism, but also may precipitate its onset. 

Universal thyroxine supplementation in extreme preterm infants does not improve neurodevelopmental outcome (van Wassenaer et al., 1997a). However, subgroup analysis of the developmental scores of infants <27 weeks gestation in the thyroxine group, compared to placebo, were increased by 18 points, but decreased by 10 points in infants of 27—29 weeks. Thyroxine supplementation may be detrimental in some infants and there are no indications, apart from gestation, why this should be so. With this uncertainty, we believe that the correction of iodine deficiency is the first and safest approach to the correction of hypothyroxinemia. 

Thyroid disorders are common in all populations, but the occurrence and the pattern of disease depend on the iodine intake of the population. The association between iodine intake level and the risk of disease is U-shaped, as both low and high iodine intakes are associated with an increase in the risk of thyroid problems. The curve is nonsymmettical with the most serious problems associated with iodine deficiency, which should be corrected. However, the iodine intake should only be brought to the level where iodine deficiency disorders are avoided. Optimally, the iodization program should be planned to keep population iodine intake within a relatively narrow range around the recommended level. 

The most serious problems are associated with iodine deficiency, which should be corrected. 

Neonates, and especially preterm infants, are a population at risk of suffering the consequences of iodine deficiency because of the impact of neonatal hypothyroxinemia on brain development. We evaluate the possible association between mental development scores at different ages and iodine intake during the neonatal period. Sixty-seven preterm infants were subdivided into GA groups for data analysis. The mental development scores reported here are those of the Brunet-Lezine scale index for children (0-24 months of age). The children were tested at 6, 9, 12, 18 and 24 months of postnatal age, and results were corrected for their GA. The test assesses P, motor abilities and postural... 

Early correction of hypothyroidism due to congenital defects in neonates has now become a standard practice in most developed countries in order to prevent longterm brain damage (Dussault and Glorieux, 1989). The more severe the fetal hypothyroidism, as indicated by bone retardation, the more Hkely are residual effects (Dussault and Glorieux, 1989). Such considerations indicate the urgent need for a preventive approach to the correction of iodine deficiency for developing countries, because treatment of individual cases is not usually possible. 

Further studies in sheep of the effect of correction of iodine deficiency by iodized oil injection at 100 days gestation (end of second trimester) revealed only partial correction of the effect on brain strucmre by the end of gestation (Potter et al.y 1984). This requires follow-up with observations of behavior and neurological stams into the postnatal period. Such studies could also be carried out in marmosets (primate model) with greater relevance to humans. However, the finding in sheep is consistent with observations in humans that the injection of iodized oil in the latter half of pregnancy may not prevent cretinism in the infant (Pharoah et al., 1971). Similar observations have been made by Cao et al. (1994) in China. 

The term iodine deficiency disorders (IDD) has been generally adopted to denote the spectrum of diverse effects resulting from iodine deficiency in a population, which are all preventable by correction of iodine deficiency (Hetzel,... 

This is quantitatively probably the most frequent component of the IDD spectrum. Cerebral hypothyroidism refers to the effect of hypothyroidism on the brain in childhood and adult life, in contrast to the effect on the fetus and in early infancy. There is a more striking effect of hypothyroidism on the brain than on other organs. This produces the characteristic mental torpor and apathy characteristic of the iodine-deficient subjects - it can be reversed at the population level by correction of iodine deficiency, just as it can be reversed in an individual patient by treatment with thyroid hormones (Hetzei, 2004). In a severe endemic, 30-70% of the population may be suffering from cerebral hypothyroidism, as indicated by a low serum thyroxine level (T4) (Buttfield and Hetzei, 1967 Kochupillai ft (S /., 1973). 

This condition is not reversible, but can be completely prevented by correction of iodine deficiency before pregnancy. 

Cretinism is a condition of severe physical and mental retardation due to iodine deficiency, and specifically due to deficiency of thyroid hormones during early pregnancy. This condition is irreversible, even after treatment with thyroid hormones or iodine soon after birth, but can be corrected if treatment with iodine starts prior to or early in gestation. 

Mental retardation Present, often Present, less severe Severe iodine deficiency (ID) Correction of iodine... 

Neurological cretinism is caused by severe iodine deficiency during pregnancy and is characterized by severe mental retardation and neurological and motor abnormalities it can be corrected by the administration of iodine before conception. The clinical features of cretinism and CH are different. 

The above-mentioned facts form the basis of a new concept of the adverse effects of not only maternal hypothyroidism, but also maternal hypothyroxinemia without overt hypothyroidism, on fetal brain development. This concept focuses on the necessity for therapeutic correction of maternal hypothyroxinemia detected in pregnancy. MRS, a quantitative laboratory and imaging technique, may be used to show the effects of hypothyroxinemia due to iodine deficiency and its correction in the human brain in an objective manner. 

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