Hypothyroidism – Low Thyroid Function

The thyroid gland, located in the neck, plays a role in metabolism, heat regulation and energy levels. Thyroid hormones are required by every cell in the body, so an under-functioning thyroid gland can lead to many symptoms.


  • Tiredness
  • Cold hands and feet
  • Poor sleep
  • Hair loss
  • Weight gain
  • Low libido
  • Constipation
  • Depression
  • Dry skin
  • Infertility 

Thyroid hormones can be tested to see if they’re out of balance and you have hypothyroidism.

Contributory Factors

Poor nutrition: the building blocks of thyroid hormones are tyrosine, which comes from protein, and the mineral iodine. The minerals selenium, iron, zinc and copper are also needed to convert thyroid hormones into their active form. Deficiencies of any of these nutrients, consumption of high levels of substances that deplete them or high levels of factors that prevent absorption can all lead to impaired thyroid function.

Low tyrosine levels can be detected by an Amino Acid Profile. Smart Nutrition can assess your dietary levels of other important nutrients and put together a specific diet and supplement plan to correct any deficiencies and boost your thyroid function. 


Imbalance in essential fatty acids: essential fatty deficiency and essential fatty acid excess can both compromise thyroid function.

A Fatty Acid Test identifies deficiencies or excesses, which you can then correct with the help of Smart Nutrition’s dietary and supplementation guidance. Please use the button at the bottom of the page to find out more.

Stress: because some of our stress hormones are made from tyrosine, at times of chronic stress the body’s resources get diverted, leaving thyroid function compromised. Cortisol, the body’s main stress hormone, prevents thyroid hormones from being converted to their more active form, which further compounds the problem.

If you have a stressful lifestyle and suffer from some of the symptoms mentioned above, an Adrenal/Thyroid Test combines thyroid hormone testing with stress hormone level analysis, so that the impact of one set of hormones can be measured against the other. 

Toxic metals: some toxic metals, such as mercury and lead, can interfere with the conversion of thyroid hormones to their active form.

High levels of these minerals can be detected by either a Urine Test or a Hair Mineral Analysis Test. If toxicity is identified, Smart Nutrition can then put together a personalised detoxification programme to help remove the metals and restore your thyroid function.

Hormonal imbalance: an excess of the female reproductive hormone oestrogen can block the action of thyroid hormones. This means that even when the thyroid is producing normal levels of hormones, symptoms of hypothyroidism appear. This is common during the menopause.

The impact of hormone imbalances on thyroid function can be assessed by a Thyroid Test. The results can then be used by Smart Nutrition to put together an effective treatment plan to tackle any hormonal imbalances and boost thyroid function. 

Oxidative stress: this term refers to high levels of the cell-damaging molecules called free radicals. Excessive free radical production can result from sources such as environmental pollutants, cigarette smoke, drugs and radiation, and there is growing evidence supporting their role in disease. They are known to suppress thyroid hormone production and prevent conversion of thyroid hormones to their active form.

An Oxidative Stress Analysis measures the body’s oxidative stress status, indicating whether this is a contributing factor to your low thyroid function. 

Low liver function: the liver is the organ responsible for converting thyroid hormones to their active form – if it’s not working efficiently the thyroid hormones can’t do their job properly.

Useful Links

Please do not return samples to the laboratories that may arrive after Wednesday 27th March and up to and including Monday 2nd April.

The laboratories are closed from the 28th March – 2nd April for the Easter Holiday.