Bakers start producing bread with iodised salt this weekend.

By law they must now use the ingredient to introduce iodine to New Zealanders' diets and help to overcome the risk of iodine deficiency.

Only organic and unleavened bread will be excluded from the requirement to use iodised salt.

Bread baked with iodised salt will not taste any different.

Iodine is an essential nutrient for good health and iodine deficiency is a global health concern and a re-emerging health problem in New Zealand.

The World Health Organisation says iodine deficiency causes brain damage, mental impairment and thyroid diseases including goitre, a large swelling on the neck from an enlarged thyroid gland.

Despite increased access to iodised salt around the world over the past decade, WHO says that in 54 countries the intake of iodine is still too low.

Food Standards Australia New Zealand (FSANZ) developed a mandatory iodine fortification standard to help deal with iodine deficiency.

- NZPA