Iodine and Food

New Zealand Listener, Volume 18, Issue 446, 9 January 1948, Page 14

Iodine and Food

| (Written for "The Listener" by

DR

MURIEL

BELL

Nutritionist to the

Health Department)

HERE is accumulating evidence that lack of iodine is related. to the production of goitre. To prevent defective intake of iodine is worth while for two reasons-first, becatise the toxic form of goitre is responsible for much disfigurement, nervous trouble and disablement of the heart; secondly, because lack of action of the thyroid gland may result im cretenism in the coming gen-~ erations, As ordinary foods in New Zealand ere not very good sources of iodine, iodised’ salt has been made available. The onus is still on the housewife, or the camp quartermaster, or the hospital house-steward, or the boarding-school matron to ask for iodised salt. Merchants need to be warned well in advance if orders are to be placed for large bags of iodised salt. The price difference on large bags is only about 10/- per ton, whereas it is uneconomic to get the small bags for institutional cookery, for then the price difference is more like £10 per ton, Presumably here lies the. reason why we hear of instances where growing children in schools or youths in hostels are not being supplied with this important item in their food. One teaspoon of iodised salt per day is sufficient to give New Zealanders their necessary quota-used in cooking porridge, meat, fish and vegetables, etc. It is important that the vegetable water should be used, as about two-thirds of the added salt may be present in the liquid. Compare this with the difficulty of getting the same amount from foods. It takes the following quantities to supply the same amount, namely, 0.2 milligram iodine present in a teaspoon of iodised salt; Cod-liver oil, 3 dessertspoons; cab- © bage, 91b.; bread, 44lb.; salmon, 10o0z.; crayfish, 100z.; oysters, 100z. (about 26 oysters); meat, /91b.; potatoes, 14Ib.; milk, 14 pints. On the other hand, two teaspoons of seameal contain 0.2 mg. iodine. Seameal is rather useful because it forms the basis of a milk puddinguseful when rice is unavailable and eggs not plentiful. The milk needs to be heated to get the jelly to form. There is a jelly-making principle named alginic acid which can be manufactured from , seaweed, and which will set when cold milk is used. This has the’ advantage that it is quickly made, needs no fuel, and again isa way of serving milk; but the necessary quantity of iodine is not there, therefore it cannot be regarded as a substitute for seameal itself. Sometimes expectant mothers are ordered not to use common salt, or baking soda, or other sodium salts, especially in the later months; seameal should then be used, ~ because the expectant mother particularly needs iodide both for ‘herself and for the growth of the offspring. Another practical point is worth mentioning. When salt gets damp, the moisture dissolves the iodide, and then, as (continued on next page)

(continued from previous page) the salt dries, the evaporation of the water takes place from the surface, some of the iodide therefore getting removed from the salt. This process of leaching may cause considerable. loss of the iodide. The housewife is advised to avoid this loss by tufning out her salt into glass jats with lids. If any of her preserving jars have been cracked, they can still serve this useful purpose.