One of the more unusual nutritional concerns for New Zealand, and the people who live here, is the low level of iodine in our soil and the reliance on food for this important mineral.

Unfortunately crops grown in iodine-lacking soils are also low in the mineral. As a result iodine was added to a food stuff that was common in the diet and used regularly - salt.

However, attributing high intakes of sodium from various sources to hypertension in susceptible people, and recent nutritional recommendations encouraging less use of salt and salty foods, levels of both sodium and salt in the diet have decreased.

Combined with the increasing use of non-iodised gourmet salts and changes in manufacturing methods, the result has been a drop in iodine levels in the New Zealand diet.

Seafood is a good source of iodine, but many New Zealanders fail to eat sufficient quantity. The likes of mussels and oysters are good sources, but are not eaten often enough to be provide the necessary levels.

Other foods, such as bread, cereals and milks, may need to be fortified with this important mineral to provide adequate intakes for all New Zealanders and especially children. Children in homes where salt is limited or restricted may be at special risk. Although we only need a very small amount (excess is harmful) getting the right amount from food is difficult. Try to eat more seafood (mussels, oysters, flesh fish) and always use Iodised salt.