Graves’ disease is an autoimmune disease that often takes years to properly diagnose, where the body produces antibodies to a thyroid receptor. It often first becomes active during teenage years and affects up to 2% of the female population. Like many autoimmune disorders, it is more common in females than in males. It often takes years for doctors to diagnose the disease as the symptoms are often confused with psychiatric ones, and the disease itself can have a fluctuating course.
In Graves’ disease, the thyroid becomes overactive, producing an excessive amount of thyroid hormone. The patient may present with nervousness, anxiety, weight loss, heat intolerance, excessive sweating, rapid pulse, weight loss, and changes in the soft tissues of the body or any combination of those symptoms. Many apparent symptoms in otherwise healthy individuals, who do not have thyroid disease, often lead the doctor astray. For example, nervousness is common in many people. Thus, clinical findings may be unmistakable or easily confused with other disorders.
The two so-called diagnostic signs of Graves’ disease are a characteristic bulging of the eye, and a rare skin disorder on the lower legs called myxedema. It can also cause a goiter or enlargement of the thyroid gland. Luckily, thyroid blood tests often make the diagnosis easier, especially detection of antibodies against the thyroid receptor. In addition, TSH is often low and other thyroid tests high in Graves’ disease. However, the thyroid hormones can go up and down and thus the disease can go on for years undetected. Alternatively, it can “burn out,” if another thyroid disease co-occurs (autoimmune thyroiditis) leading to hypothyroidism.
Last week, Dr. Tetsuyuki Yasuda and colleagues at the Osaka University School of Medicine in Japan published evidence that Graves’ disease is yet another possible presentation of vitamin D deficiency.
Yasuda T, Okamoto Y, Hamada N, Miyashita K, Takahara M, Sakamoto F, Miyatsuka T, Kitamura T, Katakami N, Kawamori D, Otsuki M, Matsuoka TA, Kaneto H, Shimomura I. Serum vitamin D levels are decreased and associated with thyroid volume in female patients with newly onset Graves’ disease. Endocrine. 2012 May 1. [Epub ahead of print] No abstract available.
They studied 26 patients with newly onset Graves’ disease, comparing them to 46 healthy controls, finding those with Graves’ disease were more likely to be vitamin D deficient and that their vitamin D levels directly corresponded with thyroid mass: the lower the vitamin D level, the more swollen the thyroid.
The authors also pointed out that animal studies have shown that vitamin D-like drugs inhibit inflammation in thyroid cells and that other autoimmune diseases, such as rheumatoid arthritis, lupus, inflammatory bowel disease, MS, and type-1 diabetes are closely linked to vitamin D deficiency.
The clinical trials that will answer the pressing question, “Does vitamin D help prevent or treat these diseases?” are currently ongoing. We are all eagerly awaiting the results, although we believe that anyone with Grave’s disease should take at least 5,000 IU/day of vitamin D, so they won’t be vitamin D deficient.