Hypothyroidism – how it can affect your energy, mood and fertility

Hypothyroidism is a condition that, traditionally, is characterised by low levels of thyroid hormone (such as thyroxine), which in turn can lead to symptoms such as:

• Tiredness
• Sensitivity to cold
• Weight gain
• Constipation
• Depression
• Slow movements and thoughts
• Muscle aches and weakness
• Muscle cramps
• Dry and scaly skin
• Brittle hair (or hair thinning) and nails
• Loss of libido
• Pain, numbness and a tingling sensation in the hand and fingers (carpal tunnel syndrome)
• Irregular or heavy periods 
• Infertility

 And more....(Source: NHS)

The diagnosis of hypothyroidism is usually made on the basis of a blood test, where there are raised levels of TSH (thyroid stimulating hormone, which is secreted by the pituitary gland at the base of the brain) and low levels of thyroxine (one of the chief thyroid hormones – also known as ‘T4’).

However, T4 is not very metabolically active, and essentially needs to be converted into what is known as T3 to exert its beneficial effects in the body. In some individuals, they can not convert T4 to T3 efficiently, and can end up still being low in T3 and hypothyroid despite having normal T4 and TSH levels. In the UK, T3 levels are rarely assessed during a conventional blood test (although this can be tested for privately) as well as thyroid auto-antibodies which, some studies suggest, can substantially increase your risk of miscarriage.

Furthermore, in order for your thyroid gland to work effectively, it needs an adequate intake of Iodine (Iodine is required for the synthesis of T4).  As Iodine is found in seafood, including kelp, many women will be deficient in Iodine as many people do not eat enough fish in the UK. Indeed, recent research published in the Lancet suggest that as many as half of young girls / women may be mildly iodine deficient (the research concluded that low levels of iodine during pregnancy can lower a child's IQ and reading ability).

T4 and T3 are also dependant on adequate dietary intake of selenium (which is directly dependant on soil levels) and Zinc and an impaired cellular response to T3 can be exacerbated by low zinc levels and iron deficiency (which is relatively common, especially among women).

So, what to do if you have any of the above symptoms?

I would recommend seeing if your GP would test for thyroid function (despite the fact that T3 levels are not usually assessed) as it is still a useful screening tool and to check for any other reason for your symptoms. Private testing can assess your T3, Thyroid autobodies status and Iodine levels.

Making sure your eat enough fish, wholegrains and iron rich food (the best source is red meat, although there are good plant based iron sources) would also be a sensible approach. If you are already deficient in these nutrients (Iodine, Iron, Zinc, Selenenium etc), then supplementation to correct a deficiency may be the best course of action, especially if you do not eat fish and / are vegetarian, for example. 

Please, however, seek professional guidance before second guessing what your body might need, as too much iodine can induce hyperthyroidism (in other words, do you just take extra Iodine “in case it helps” nor any other supplement at high doses for similar reasons).