Most patients should supplement iodine or get plenty food rich in this element, especially pregnant women!

Thyroid , Iodine [Iodum, in Dutch: Jodium] and more-the body's oven. 

יוד ובלוטת התריס ועוד

After having written quite a bit about vitamin B12 and Vitamin D and the dire consequences these vitamins can have on all aspects of health when they are deficient [and this is often the fact] today I will write about an old problem which seems to be rapidly resurging and -if not recognized -can have serious consequences as well as you will read below.
Iodine is found in trace amounts in the human body, and is essential for the synthesis of thyroid hormones.[T4 and T3]
Thyroxine (T4) and triiodothyronine (T3) are essential to human life. Without sufficient iodine, our body is unable to synthesize these hormones, and because the thyroid hormones regulate metabolism in every cell of the body  iodine deficiency can have a devastating effect on our health
Severe iodine deficiency results in reduced thyroid hormone synthesis .The thyroid gland may become enlarged and this is called goiter or struma.
In populations where there is a severe iodine deficiency one can find many cases of hypothyroidism often with a goiter[“swollen neck”] , and cretinism in young children [severe hypothyroidism resulting in physical and mental stunting in children],
Severe iodine deficiency during pregnancy or infancy causes cretinism, manifesting it self in severe mental retardation, stunted physical growth, deafness, spasticity and a squint.
I have not seen cretinism in Israel.
If discovered early enough cretinism can be corrected with iodine supplementation.
A few clinical remarks:
It is advisable that every women checks the thyroid function before pregnancy or as early as possible.
The most common useful test is : TSH
Alas, as with vitamin B12 the values that the laboratories mention as “normal values” are not always trustful.
Nothing is yet totally sure [even after so many years of research],but a normal thyroid test [TSH] should be somewhere between 1.0-2.0 mU/L.
Sometimes the TSH test alone is not enough and T4 and T3 may also have to be tested ,as well as the freeT4 and the free T3, but leave this all to your doctor.
I advise every pregnant women with some doubt about the thyroid test to consult a endocrinologist! [as well as nutritional orientated doctor]at least once during early pregnancy, as the issue can be quite complicated,
Please, don't listen here to “good advise” of friends who are dealing “a bit” in alternative medicine.

The most common symptoms of hypothyroidea /hypothyroidism are:

1. Generalized

Goiter (enlargement of the thyroid gland)

Fatigue  or weakness : always!

Generalizedmuscle weakness[tired muscles while combing hairs!]

Lethargy :nearly always

Cold intolerance :nearly always

Cold hands and feet

Weight gain despite diminished food intake

Edema,.also ankle edema [water retention]]

puffy face ,facial edema

Arthralgias [joint complaints]

Slow speech : in 9 of 10 patients

Hoarseness

2. Neuropsychiatric

Diminished libido

Headache

Slow thinking

Forgetfulness ,in many patients

3. Gastrointestinal

Constipation :quite often

4. Dermatologic

Dry or coarse skin ,nearly always!

Decreased sweating : very often

Hair Loss (especially outer third of eyebrows)

Broken nails

Skin may show yellow-orange discoloration

Dry coarse brittle hair

5. Gynecologic

Amenorrhoea[no menstruation 

or  Menorrhagia [heavy periods]

Hypothyroidism should be heavily suspected in  all [elderly] patients with depression

Iodine deficiency can further be the reason for , decreased fertility , miscarriage, premature birth, lower birth weight, increased perinatal mortality, and an increase rate of congenital anomalies and ADHD in later age.
In humans, most of the growth and development of the brain occurs during the fetal
period and the first two to three years of postnatal life. Consequently, iodine deficiency, if severe enough to affect thyroid hormone synthesis during this critical period, will result in hypothyroidism and brain damage with irreversible mental retardation.
Iodine deficiency is the world's greatest single cause of preventable brain damage.
Even a mild deficiency can lead to decreased intellectual functioning.
Except from a vital role in metabolic processes iodine has been also found useful for many other minor or major problems.
Iodine deficiency may impair the function of the immune system.
In Holland Dr. Moerman -z"l-has shown that iodine is probably vital in the prevention and treatment of cancers.
Iodine may also  prevent breast cysts [ fibrocystic breast disease], characterized by painful swelling in the breasts .
Iodine has been even suggested for conditions like Dupuytren.[thickening of the skin in the palms of the hand ,which can cause contractions of the fingers].
A saturated iodine solution [ka.jodide,kal.iodine] can be an excellent help in some cases of bronchitis.

Very good food sources of iodine include sea weed [atzot yam,like kelp], yogurt, cow's milk, eggs, strawberries and mozzarella cheese. Fish in general is also a good source of iodine.