A new study suggests that a thyroid medication often prescribed to older Americans may be linked to bone loss, a common problem in old age.
Levothyroxine is a synthetic hormone often prescribed to treat hypothyroidism. People with this condition do not produce enough thyroxine, which can lead to weight gain, fatigue, hair loss and, ultimately, serious and fatal complications.
An estimated 23 million Americans take levothyroxine daily. Researchers say some people take it for so long that it is not clear what caused them to start taking it.
“The data suggest that a proportion of the thyroid hormone given to older adults without hypothyroidism is harmful,” said study leader Dr. Elena Ghotbi, a postdoctoral research fellow at Johns Hopkins University School of Medicine in Baltimore.
The normal range for thyroid-stimulating hormone (TSH) in the blood is between 0.4 and 5.0 microunits per milliliter. If it is increased, it is associated with an increased risk of bone fractures.
