Iodine Deficiency Symptoms - Impact on Babies and IQ of children

Iodine is an essential nutrient element that is critically required for the body to produce the thyroid hormone. Iodine deficiency can lead to the enlargement of the thyroid gland and to mental retardation in children whose mothers consumed inadequate iodine during pregnancy.

Prior to 1930 iodine deficiency was common in certain parts of Canada, USA, Britain and other countries. The addition of iodine to common salt has improved the situated in developed countries.

There is also greater awareness of the problem and how to prevent iodine deficiency symptoms by eating food that naturally contain iodine, such as dairy products, seafood and soy products.

However the problem remains in less developed countries and about 40% of the world's population remains at risk for iodine deficiency.

Despite the progress that has been made, women in the UK have been warned recently, that even mild iodine deficiency during pregnancy could be reducing the intellectual capacity of their babies.

Recent research, that included 1,000 families, found a correlation between lower IQ's and reading score for primary school children whose mother had insufficient iodine while pregnant.

About two thirds of the women tested had iodine deficiencies during their pregnancies.

This article discusses this research and highlights the recommended amount of iodine required every day and the best natural dietary sources of iodine.

The researchers have advised women of child-bearing age to check and make sure that they maintain adequate iodine levels in their diets by eating dairy products, soy products, fish and other natural sources of iodine.

Location of the Thyroid, which can become enlarged and cause swellings in this area of the neck due to Iodine deficiencies. Source: Public Domain

Iodine Needs, Deficiencies and How Deficiencies are Diagnosed

The best way to determine whether you have any iodine deficiency is to have a urine test.

Iodine deficiency is defined as a urinary iodine concentration less than 50 micro g/l. This requires a daily intake of 150 micro g /day.

1 - 8 years boys and girls # 90 micro g/day

9 - 13 years boys and girls #120 micro g/day

14-18 years boys and girls # 150 micro g/day

19 - 70 years men # 150 micro g/day

19- 70 years women # 150 micro g/day

Women During Pregnancy # 220 micro g/day

Women During Lactation # 270 micro g/day

The table below summarizes the various levels of iodine decificincy and how it relates to levels of iodine in the urine and associated dietary intakes of iodine.

Foods Rich in Dietary Iodine

(see Details in table Below)

Dairy Products

Cow's milk
Cheese
Yogurt
Frozen Yogurt
Ice Cream

Eggs

Supplements

Iodine-containing multivitamins
Iodized table salt

Seafood

Saltwater fish
Shellfish
Seaweed (including kelp, dulce, nori)

Soy Products

Soy milk
Soy sauce

Research on Iodine Deficiencies in Pregnant Women in UK

A study of 1,000 families has shown that mild iodine deficiency is still relatively common affecting two-thirds of the women in the study.

Children of women with an iodine-to-creatinine ratio of less than 150 micro g/g (urine Iodine concentrations less than about 100 micro g/l) had:

Lower IQs at the age of eight

Worse reading ability aged nine.

The study suggested that iodine deficiencies during pregnancy may produce risks that a child may not reach their full potential.

The British Dietetic Association recommends that pregnant and breastfeeding women need a minimum of 250 micrograms of Iodine per day and other adults need at least 150 micrograms of Iodine per day.

What Levels of Iodine Intake Causes Known Deficiencies?

The table below summarizes the Iodine levels in the urine, equivalent intake levels from food and the associated level of deficiency.

Iodine Intake Requirements and Deficiency Status

Median Iodine Level in the Urine	Iodine Intake to Maintain Urine Level Specified	Iodine Deficiency Status
Recommended Level in Urine - greater than 100 micro g/l	Recommended Dietary Allowance for iodine in adult men and women is 150 micro g per day
less than 20 micro g/l	less than 30 micro g/ day	Severe deficiency
20-49 micro g/l	30-74 micro g/ day	Moderate deficiency
50-99 micro g/l	75-149 micro g/ day	Mild deficiency
100-199 micro g/l	150-299 micro g/ day	Optimal
200-299 micro g/l	300-449 micro g/ day	More than adequate
more than 299 micro g/l	more than 449 micro g/ day	Possibly Excessive with Overdose Symptoms

Iodine Levels in Common Foods per Typical Serving or 100g

Food	Serving Size	Average iodine content per serving (micro g)
Oysters	100g	160
White fish	100g	115
Sushi (containing seaweed)	100g	92
Shellfish	100g	90
Yoghurt	150g	75
Cow's milk	200ml	65
Tinned salmon	100g	60
Oily fish	100g	50
Bread (made with iodised salt)	100g	46
Organic cow's milk	200ml	45
Steamed snapper	100g	40
Cheddar cheese	100g	23
Eggs	100g	22
Ice cream	100g	21
Eggs	1 egg (50g)	20
Chocolate milk	100g	20
Flavoured Yoghurt	100g	16
Cheese	40g	15
Regular milk	100g	13
Meat	100g	10
Poultry	100g	10
Canned tuna	100g	10
Nuts	25g	5
Bread	1 slice (36g)	5
Fruit and veg	1 portion (80g)	3
Bread (without iodised salt)	100g	3
Beef, pork, lamb	100g	1
Apples, oranges, grapes, bananas	100g	1