Formula feed iodine

Variances in iodine content of formula feeds, and the limited number of studies, emphasize the need for carefully-conducted research to investigate the infiuences of gestation, postnatal age, intercurrent illnesses, and so on, on iodine homeostasis in preterm infants. 

Salt is consumed in all industrialized societies, in fact also in the great majority of countries with a purely rural economy. It is therefore an ideal vehicle for iodine. Food is indirectly iodized by being salted with iodized salt, in a few instances with salt of a particularly high iodine content (e.g. bread in the Netherlands). Direct addition of iodine compounds to food is impracticable and not in use, with the exception of commercial baby formula feedings. 

Consequently, the workshop recommends specific monitoring of iodine intake of mothers and infants in Europe by periodic analysis of urinary iodine levels, and to the extent feasible, of serum TSH and thyroid hormone measures. The daily intake of iodine should be at least 200 pg in pregnant and lactating women and 90-120 pg in young infants. To reach these objectives, the mothers diet should be systematically supplemented with iodine whenever necessary, by vitamins/minerals tablets as prescribed by physicians. Breast milk is the best source of iodine for the infant, and exclusive breast feeding for 4-6 months should be encouraged. However, when circumstances require that infants receive formula, the iodine content of formula milk should be increased fiom the traditional recommendation of S pg/dl milk to 10 pg/dl for full term and 20 pg/dl for premature babies. 

The aim of this chapter is to describe iodine intakes based on the calculated amounts for standard infant formulas available in the UK, and for all proprietary enteral preparations that can be used as standalone feeds for complete nutrition. The proprietary preparations highlighted in this review are those that are fisted in the British National Formulary, and the corresponding version for Children 2006 (British National Formulary for Children, 2006) mostly in the section Appendix A2 Borderline Substances excluding those which we know have been discontinued (from 2007). Enteral supplements which are not the sole source of nutrition have not been included, as potential iodine intake will be variable and dependent on the proportion of enteral supplement consumed, as well as the amount and iodine content of nonsupplemented food. 

Pregnant and lactating women are vulnerable to iodine deficiency if specialized enteral preparations are their sole source of nutrition. Only 9 out of 44 specialized enteral preparations for adults provide the current requirement of 200 pg/day. If the WHO technical consultation presently under review is accepted, then only two preparations will meet the proposed allowance of 250 pg/day. This has particular consequences for the brain development of the fetus and infant if the mother has an iodine deficiency during pregnancy and if she breast-feeds. Generally, standard infant formula are recommended for use by the manufacturers for up to 1 year, but as infants are weaned from approximately 6 months, estimation of iodine intakes can only be approximate as the mixed diet progresses. 

Iodine deficiency during the perinatal period and exposure to an iodine excess is quite conspicuos. The iodine intake of newborns is entirely dependent on the iodine content of breast milk and formula preparations used to feed them. The minimum recommended dietary allowance (RDA) for different age groups is summarized in Table 50.1. To meet such requirements, the iodine content of formulas for premature newborns should contain 20 j,g/dl, and that of first and follow-up preparations 10 j,g/dl. We refer here to these new... 

This is particularly important for infants receiving formula milk as an alternative to breast-feeding. An increase in levels from 5 to lOpg/dl has been recommended for full-term infants and 20 pg/dl for premature infants. However, breast-fed infants will be iodine deficient if the mother is iodine deficient. 

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