As of Friday, October 18, 2013
DEAR DOCTOR K: I have hypothyroidism. According to the Internet, there are several supplements that could help my symptoms. Should I be taking a supplement along with my thyroid medicine?
DEAR READER: Hypothyroidism is a condition in which the thyroid gland (located in the front of the neck) doesn’t produce enough thyroid hormones. Every cell in the body needs thyroid hormone for normal function. When there is not enough hormone circulating in the blood, symptoms develop.
The most common symptoms of hypothyroidism are fatigue, constipation, weight gain and slowed heart rate. These symptoms can be very subtle, or they can be dramatic. For example, I have a super-energetic, upbeat friend who, about 20 years ago, started to get up later and come home from work earlier. She became grouchy and irritable. I figured she had developed depression, but what she had developed was hypothyroidism. Her symptoms disappeared within a week of starting treatment.
In contrast, as a medical student I was called to see a man who had been admitted to the hospital for a slow heart rate. And it was slow, indeed. The normal rate is 60 to 80 beats per minute, and his was 35. In fact, everything about him was slow. He spoke a sentence very slowly, two seconds between every word: “Where ... is ... the ... bathroom?” He even laughed slowly. He had severe hypothyroidism.
The standard treatment is to take replacement doses of thyroid hormone — pills manufactured by drug companies. But, as several of my patients have pointed out, if you type the word “thyroid” into an Internet search engine, you’ll find a lot more: a sea of articles and advertisements promoting a range of supplements. Some supposedly improve thyroid health. Others even claim to cure hypothyroidism.
But these supplements have an unproven track record. In contrast to drugs produced by drug companies, the production of supplements is not closely regulated by the FDA.
It gets worse. Many of these supplements contain potentially dangerous levels of thyroid hormone: an uncontrolled amount of the real hormone has been added to the supplement. Anyone taking a high-dose supplement along with thyroid medication could end up suffering the harmful effects of having too much thyroid hormone in their system. The harmful effects include thinning of the bones (osteoporosis) and dangerous abnormal heart rhythms.
The most widely used supplements for thyroid health include those containing iodine, such as kelp. But more iodine does not cure hypothyroidism. In fact, a nutritional task force found that nearly all claims of supplements that supposedly enhance thyroid function are unproven.
Selenium may be an exception. Early studies show that it may prevent thyroid conditions from flaring after pregnancy. But even these findings must be confirmed by additional research before doctors can recommend using selenium for the treatment or prevention of thyroid disease.
If you have hypothyroidism, take thyroid pills, not supplements. They are safer and more effective.
Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.