Nutritional Deficiencies and the Thyroid

How familiar are the following signs and symptoms?

Exhaustion or fatigue, depression, sensitive to cold or cold hands and feet, weight gain, muscle and joint pains, carpal tunnel, painful soles of the feet, swollen or puffy face, eyes, arms or legs, menstrual abnormalities, fuzzy head, constipation, voice changes, increased response to allergies (itching, prickly hot skin, rashes, urticaria), regular infections such as sinus or thrush, dry hair, skin and nails, hair loss, thin eyebrows (outer third), high cholesterol (which doesn’t respond to medication), or haven’t been well since an infection/virus.

All of the above signs and symptoms can be associated with low thyroid function. The following signs and symptoms are associated with an overactive thyroid: weight loss without actively trying, insomnia, anxiety, irritability, panic attacks, poor concentration, palpitations, rapid pulse, high blood pressure, increased sweating, tremors, diarrhoea, tiredness, thickening of the skin, amenorrhoea or light menses, muscle pain and weakness (upper arms and thighs particularly), eye problems, bulging eyes, infertility, mood swings, fine and brittle hair.

Most commonly we see the low thyroid function symptoms presenting, however, it is all too easy to relate most of these signs and symptoms to many other conditions. Often our clients have seen their Doctor and been prescribed antidepressants or some may have had a thyroid test within the normal limits and told to go home to exercise and eat less.

The test results may continue to come back normal but the body is unable to utilise the hormones being produced. They may have thyroid hormone resistance, where the body is capable of producing the thyroid hormones, but nutritional and metabolic dysfunctions have made the tissues resistant to them. Along similar lines as insulin resistance.

When essential nutrients for thyroid hormone production are deficient in the diet, the thyroid gland enlarges in an apparent effort to filter more blood to get the scarce nutrients out of the blood supply and from over stimulation of the thyroid gland by thyroid stimulating hormone (TSH). This enlargement is diagnosed as a goitre. It is well known that iodine deficiency can cause a goitre and maybe less well known that selenium deficiency may also cause goitre.

Hypothyroidism is characterized by insufficient triiodothyronine (T3) thyroid hormone at the cellular level. Thyroid hormones regulate the metabolic rate, so people with hypothyroidism typically have a low metabolic rate. This usually results in low energy level, slow heart rate, low body temperature, weight gain and so on. Hypothyroidism can result from the thyroid gland not producing enough thyroxine (T4), or from a decreased rate of conversion of T4 into T3, the hormone that activates the cells.

Hypothyroidism can be caused by the presence of other autoimmune diseases, family history, past stomach infection or food poisoning, EBV, allergies, coeliac disease, drugs (eg lithium), chemical toxicity (dioxins), high intake of fluoride, heavy metals eg: mercury, lead, cadmium, arsenic, high intake of goitrogens, increased age and chronic stress. Fasting or not eating enough can also cause thyroid hormone levels to drop. The decrease in thyroid hormones in both of these cases seems to be a built-in safety mechanism of the body to preserve energy for healing and prevent catabolism of the muscles. It appears that for the thyroid to produce a normal amount of hormone, the body must be well. Any condition can potentially cause low thyroid output as a preservative function. This appears to be a good system for the body, because you don’t want plenty of energy if your body needs to rest and heal.

Fluoride has the potential to impair thyroid function and was used as a thyroid-suppressing medication for patients with hyperthyroidism. Fluoride was utilized because it was found to be effective at reducing the activity of the thyroid gland – even at doses as low as 2 mg/day. With so many people living in fluoridated cities and ingesting possible doses of fluoride (1.6-6.6 mg/day) that fall within the range of doses (2 to10 mg/day) once used by doctors to reduce thyroid activity in hyperthyroid patients, there is concern that current fluoride exposures may be playing a role in the widespread incidence of hypothyroidism.

Fatty acid metabolism is down regulated in those with hypothyroidism, due to the inhibition of delta 6 and 5-desaturase. This impacts on the cardiovascular system and mitochondrial function. Supplementing with EPA/DHA/GLA will bypass these enzymes and reduce the risks of fatty acid imbalances and deficiencies.

Tyrosine undergoes iodination to form mono-iodotyrosine (T1), then a second iodination produces di-iodotyrosine (T2) that then combine to produce tri-iodothyonine(T3) and tetra-iodothyronine or thyroxin (T4). Even though the body can produce tyrosine from phenylalanine, age reduces the ability to keep up with the needs of a demanding thyroid. Add into this the chronic stress that is clearly effecting many of our clients and the adrenals utilizing tyrosine at rapid rates. A deficiency of tyrosine can cause sluggishness and as a result, the body reacts by storing more calories as fat for energy.

Iodine is a trace mineral required by the body for the synthesis of the thyroid hormones, T4 and T3. T4 contains 4 iodine atoms and when one of the iodine atoms is stripped off of T4, it becomes T3, with 3 iodine atoms remaining. Under normal circumstances, the body contains approximately 20 to 30 mg of iodine, with the larger amount being stored in the thyroid gland. Smaller amounts of iodine are also found in lactating mammary glands, the stomach lining, salivary glands, and in the blood. The random or 24 hour urinary iodine test may be well worth doing if you suspect that thyroid function is not optimal. This test is also very useful for those women who suffer from fibrocystic breasts, which is related to an iodine deficiency.

Researchers suggest that an iodine deficiency impairs the function of the immune system and that adequate iodine is necessary to prevent miscarriages (a common link to hypothyroidism). In addition, a dietary deficiency of vitamin A (hypothyroidism inhibits conversion of beta carotene to vitamin A), vitamin E, zinc and/or iron can exaggerate the effects of iodine deficiency. Excessive consumption of iodine can inhibit the synthesis of thyroid hormones, leading to the development of goitre and hypothyroidism. Excessive iodine intake may also cause hyperthyroidism, thyroid papillary cancer, and/or iodermia (a serious skin reaction). Interestingly, iodine deficiency can also cause hyperthyroidism.

Selenium, a trace mineral well known for its strong antioxidant properties and natural synergism with other vitamins, is involved in the conversion of T4 to T3 by the removal of an iodine molecule from T4 (5-deiodinase). The removed iodine molecule then gets returned to the iodine pool to be reused for additional thyroid hormones. Studies have shown that selenium supplementation reduces inflammation in autoimmune thyroiditis.

Completing a hair tissue mineral analysis test (HTMA) is a useful tool due to the link between T4 and its ability to alter the detoxification ability of the liver. Low T4 can activate phase I detoxification by triggering cytochrome P450 isoenzymes. This then imbalances phase II detoxification and increases free radical production, leading to increased lipid peroxidation and the link to atherosclerosis and heart disease in hypothyroidism. This test also gives the ratios of minerals. The calcium to potassium ratio is of particular interest because potassium is necessary to sensitise the tissues to the effects of T4. Studies have shown hypothyroidism increases intestinal absorption of calcium with lower than normal excretion via the kidneys. This elevation of calcium in relation to potassium is indicative of hypothyroidism as lower calcium to potassium ratio indicates a trend toward hyperthyroidism.

Basal temperature charting is in my opinion a very fascinating tool. It provides valuable information, which reflects metabolic rate, adrenal activity and reproductive hormone movement. Charting for three months minimum gives a good range of information, especially if you suspect adrenal exhaustion is an underlying factor. It allows us to track the client’s progress and is a good interaction tool with them, which I have found leads to better compliance.
Thyroid disorders can stem from many causes and identifying specifically what that is can aid in personalising the treatment. For example, if chronic stress is presenting tyrosine (for adrenal hormones), magnesium (improves the function of the adrenal glands), B vitamins (esp. B5) and vitamins A (lowers elevated cortisol), C (protects against the toxic effects of cortisol and may lower its production) all support the adrenals. There are several tools, which can be used to support differential diagnosis and therefore guide your treatment. Thyroid conditions respond well to nutrient treatments and herbs alike.

Written by Carolyn Fletcher (McSweeney). Carolyn is a Clinical Medical Herbalist, Clinical Nutritionist, Neuro-linguistic Programming (NLP) Master Practitioner, HNLP Coach/Counsellor, Live Blood Analysis consultant (Haemaview) and has a National Certificate in Adult education and Training.