Hashimoto’s disease (Hashimoto’s thyroiditis) is an overlooked scourge that leads to hypothyroidism and is particularly widespread among women. Postpartum thyroiditis that also slows down your metabolism follows in the wake of pregnancy. Graves’ disease where the metabolism speeds up (hyperthyroidism) is less common. These three thyroid disorders belong to the group of autoimmune disorders where the immune defense attacks the body’s tissues, and it appears that lack of vitamin D increases the risk, as it controls the immune defense in a number of ways. According to a new review article that is published in Nutrients, taking larger quantities of vitamin D may have a positive impact on these thyroid disorders.
An estimated five percent or so of the world’s population suffers from autoimmune thyroid disorders. The number is on the rise and most people have still not been given the proper diagnosis or treatment.
Hashimoto’s disease that causes the metabolism to slow down (hypothyroiditis) is the most common thyroid disorder and is particularly common among women. The symptoms are insidious and include increased fatigue, difficulty with concentrating, and poor memory, which is often mistaken for menopause or old age symptoms. There are also other symptoms like goiter, cold sensitivity, weight gain, swollen neck, dry skin, constipation, coarse and deep voice, low libido, despair, and a tendency to feel depressed.
Hashimoto’s disease is caused by chronic inflammation where antibodies attack the hormone-producing thyroid cells. Lack of thyroid hormones slowly steps up the number of symptoms, depending on which tissues that are starved of energy.
Graves’ disease is also an autoimmune disease, where the antibodies attack other parts of the thyroid gland, which leads to hyperthyroidism This may result in goiter, increased heart rate and heart palpitations, increased sweating, trembling hands, frequent and loose stools, weight loss, fatigue, inner unrest, nervousness, and other psychological symptoms. Approximately five percent of patients with Graves’ disease have glossy, bulging eyes.
Postpartum thyroiditis typically occurs right after pregnancy and is caused by an inflamed thyroid gland. Following a phase of increased thyroid activity, the metabolism slows down (hypothyroidism) and this may require medical treatment.
Factors that are known to lead to autoimmune thyroid disorders include lack of selenium, too little or too much iodine, smoking, virus infections, radiation, stimulants, and stress. It also appears that the widespread problems with vitamin D deficiency is an overlooked factor.
The thyroid hormones
Vitamin D’s immunoregulatory effect
Vitamin D is commonly associated with the body’s calcium uptake and bone health, but more and more research points to vitamin D as being vital for a number of other functions. Most of the body’s cells and tissues have vitamin D receptors (VDR) that control a long list of genes and physiological processes, including the body’s innate immune defense system that combats most infections. The same goes for the body’s adaptive immune defense that develops after we are born and which consists of T lymphocytes, B lymphocytes, and antibodies.
Studies show that the immune system is unable to work properly and cannot be activated without the presence of vitamin D. Also, if we have too little vitamin D to regulate our immune defense, we risk that it overreacts with chronic inflammation. Research shows that vitamin D regulates the immune defense by suppressing the T lymphocytes’ production of pro-inflammatory cytokines that are heavily involved in autoimmune diseases. The scientists behind the new article in Nutrients wanted to take a closer look at vitamin D and its role in the development and management of autoimmune thyroid disorders.
Hashimoto’s disease and vitamin D
Hashimoto’s disease is more specific than a T-cell-mediated autoimmune disorder that is characterized by circulating anti-thyroid peroxidase (TPOAb) and/or anti-thyroglubulin (TgAb) antibodies and infiltration of the B and T lymphocytes of the thyroid gland. The increased immune activity results in varying degrees of impaired thyroid function and reduced production of thyroid hormones (T4 and T3).
An increasing number of studies have shown that over 60 percent of people suffering from Hashimoto’s thyroiditis lack vitamin D. The more vitamin D you lack, the more likely you are to develop the disease.
In recent years, studies have shown that vitamin D supplementation has a positive effect. One study (Simsek et al.) was carried out on 82 patients with Hashimoto’s thyroiditis. They were divided in two groups. One group got 25 micrograms of vitamin D daily for a month, while the other group got matching placebo. After one month, the scientists could see that the patients in the vitamin D group had significantly lower levels of TPOAb and TgAb antibodies, which is a sign of a more normalized and less overactive immune defense.
Other studies have showed pretty much the same and have also demonstrated that vitamin D supplementation can lower levels of thyroid-stimulating hormone (TSH), which is known to be elevated during the initial stages of the disease.
The reason why vitamin D supplementation has been unable to demonstrate an effect in some studies is that patients did not lack the vitamin or that they had been given too low a dose. Lack of magnesium may also explain it, as magnesium-containing enzymes are involved in the activation of vitamin D.
Graves disease and vitamin D
Graves’ disease, also known as Basedow’s disease, is the most common cause of hyperthyroidism. Autoantibodies (TRAb) attack the site where they thyroid gland binds thyroid-stimulating hormone (TSH), causing the thyroid gland to become increasingly overstimulated and eventually develop a benign enlargement known as goiter. The disease primarily attacks younger and middle-aged women, but it is also seen among men.
Studies show that lack of vitamin D is twice as common among patients with Graves’ disease that have not been helped by conventional therapy. Other studies show a link between low blood levels of vitamin D and goiter in women, who have recently developed Graves’ disease.
Only few studies of vitamin D supplementation of Graves’ patients are available, and the results are not too reliable. However, it appears that having adequate levels of vitamin D in the blood helps prevent the disease, and it is always a good idea to take a vitamin D supplement if your levels are too low.
Postpartum thyroiditis and vitamin D
Postpartum thyroiditis, which is also an autoimmune thyroid disorder, normally occurs in the first year after giving birth. The disease usually starts by speeding up the metabolism (hyperthyroidism) and then slows it down (hypothyroidism). Postpartum thyroiditis is often confused with stress symptoms in the new mother. Most individuals that develop postpartum thyroiditis return to normal thyroid function after 12-18 months. This disease may require medical attention.
Different studies have shown a link between low levels of vitamin D, postpartum thyroiditis, and levels of parathyroid hormone (PTH) that is relevant for the body’s calcium turnover.
The new article in Nutrients concludes that there is a link between lack of vitamin D and thyroid disorders. High-dose vitamin D supplements may therefore have a positive impact on autoimmune thyroid disorders.
Additional information about iodine, selenium and the metabolism
Our metabolism also depends on iodine and selenium. As mentioned earlier, iodine supports the thyroid hormones, T4 and T3. We also need selenium-containing enzymes to remove an iodine atom from the passive T4 hormone and convert it to active T3. Selenium-containing antioxidants also protect the thyroid gland against oxidative stress and inflammation. You can read more about that by clicking on the following link
Chiara Mele et al. Immunomodulatory Effects of Vitamin D in Thyroid Diseases. Nutrients 16 may 2020.
Andrea Rosanoff et al. Essential Nutrient Interactions: Does Low or Suboptimal Magnesium Interact with Vitamin D and/or Calcium status. Advances in Nutrition 2016
Pernille Lund. Har du problemer med stofskiftet. Ny Videnskab 2015
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