One of the essential trace minerals for good health is Iodine. According to the recent survey upto 2 billion people worldwide are suffering from iodine deficiency disorders including 285 million children of school going age. Iodine is required for the synthesis of thyroid hormones which is important to carry out many body processes including growth and brain development of a fetus during pregnancy.
Daily Iodine requirement
As mentioned earlier iodine is required for the synthesis of thyroid glands. Approximately 50 mcg of iodine is required by the thyroid glands for the synthesis of thyroxine . The recommended dietary allowance for iodine according to WHO is;
- Infants and children up to 5 years : 90 mcg
- Children 6-12 years 120 mcg
- Children over 12 years and adults: 150 mcg
- Pregnancy and lactation : 250 mcg
The requirement of iodine is higher in pregnant women due to increased thyroxine production. The deficiency of iodine in mothers can lead to miscarriages, still birth, preterm delivery , intellectual and congenital disabilities in children.
Iodine deficiency disorders
Iodine deficiency is most common in developing countries. Introduction of iodized salt in diet has vastly reduces the deficiency symptoms , however it has been estimated that approximately 40% of the world is still at risk of developing iodine deficiency. Extremely low iodine intakes for longer period of time are associated with the development of goitre which is characterised by an enlargement of thyroid glands that are visible in the neck. Hypothyroidism is another autoimmune disorder which occurs as a result of taking too much or too little iodine.
Severe iodine deficiency during pregnancy results in cretinism in infants, which results in mental deficiency, shuffling gait, shortened stature, and hypothyroidism. Less severe iodine deficiency could lead to moderate mental retardation and poorer iq levels.
Sources of iodine
Iodine is naturally present in soil and sea water. Sea foods are naturally rich in iodine . Salt water fish contains 300-3000 microgram of iodine per kg of flesh. Common sources of dietary iodine include:
- Iodized salt
- Cottage cheese
- Salt water fish
- Chedder cheese
Taking too much iodine through medications, radiology procedures or diet results in developing hyperthyroidism and hypothyroidism.