Supplementation with relatively modest amounts of L-carnitine and selenium may improve the prognosis of people with Graves' disease. According to a small Italian trial published in Nutrients, supplementation ensures that conventional medications take effect more quickly. Moreover, the combination of L-carnitine and selenium allows a higher percentage of patients to stop needing medication after a few months.

Graves' disease
Graves' disease is an autoimmune disease. The immune system attacks the thyroid gland, mistaking the receptors for the hormone TSH for a target. TSH stimulates the thyroid gland to release T4 and other thyroid hormones.

In Graves' disease, the immune system produces antibodies against the TSH receptors. Sometimes these antibodies act as anti-TSH, causing the thyroid gland to produce too little thyroid hormone. More often, however, these antibodies mimic the action of TSH, causing the thyroid gland to release too much thyroid hormone. Possible symptoms include a rapid heart rate, weight loss, tremors, and heat and exercise intolerance.

Standard treatment for an overactive thyroid caused by Graves' disease usually involves administering methimazole. Methimazole inhibits the enzyme thyroperoxidase in the thyroid gland, reducing the thyroid's ability to bind iodine to thyroid hormones—and therefore, producing less hormone.

Study
Endocrinologists from the University of Turin divided 60 adults with elevated thyroid hormone levels into two equal-sized groups. All participants had recently been diagnosed with Graves' disease. The participants were given methimazole.

Half of the participants took a capsule containing 500 milligrams of L-carnitine [chemical structure shown below] and 83 micrograms of elemental selenium in the form of selenomethionine daily with a meal, in addition to their regular medication. Three large Brazil nuts contain approximately the same amount of selenium. [Am J Clin Nutr. 2008 Feb;87(2):379-84.]

The Italians used a supplement marketed as Tiroxil 0.4. Tiroxil 0.4 is a product of Lo.Li. Pharma, but that company did not sponsor the study.

The researchers followed the subjects for 24 months. They evaluated them every two months.

Results
Every two months, the researchers measured the concentration of 'bad' antibodies in the subjects' blood (TRAb). If this concentration was less than 3.5 units per liter, they considered their subjects TRAb-negative. They assumed that the immune system had calmed down.

In the control group, it took an average of almost 14 months for the subjects to become TRAb-negative. In the supplementation group, it took 9 months. This difference was statistically significant.

During treatment, the Italians gradually reduced the methimazole dose. The initial dose was rather high, and they determined the optimal dosage based on blood counts. This was significantly lower in the supplementation group than in the control group.

If the subjects were TRAb-negative and their blood levels of TSH, free T3, and free T4 hormones were normal, the researchers stopped the medication. If the subjects were still stable without methimazole two months later, the Italians considered this a 'remission'.

In the control group, this occurred in 13 percent of the subjects, and in the supplementation group, in a remarkable 63 percent. This difference was also statistically significant.

Click on the table below for a larger version.

Mechanism
The researchers don't know exactly how the supplement works. Based on previous studies, they suspect that selenium mitigates autoimmune reactions and that carnitine reduces thyroid hormone uptake into cells. However, these mechanisms cannot fully explain the impressive effect of supplementation documented in the Italian study.

Conclusion
"Our findings provide evidence supporting the clinical benefit of adding combined L-carnitine and selenium supplementation to methimazole in the treatment of overt Graves' disease," the researchers summarize.

More soon.