Supplement Need After Thyroid Cancer Surgery Linked to Poorer Life Quality

People needing to take vitamin D and calcium supplements due to very low levels soon after thyroid cancer surgery are likely to experience a decline in their quality of life (QOL) over at least the following year, a study suggests.

As such, assessing calcium and vitamin D levels, as well as evaluating whether patients have hypoparathyroidism, are important in follow-up care, the scientists said.

The study, “Quality of life of patients more than 1 year after surgery for thyroid cancer,” was published in the journal Hormones.

Thyroid cancer is considered one of the more ‘treatable’ types of cancers, with high long-term survival rates. However, the effects of both the cancer and its treatment impact life beyond survival.

Thyroid removal can result in abnormally low levels of parathyroid hormone (PTH), or hypoparathyroidism, which in turn alters the levels of calcium and vitamin D in the blood. Treatment with calcium and active vitamin D supplements is a standard approach in such cases. But such use is associated with short- and long-term complications, such as kidney stones and renal failure, affecting a person’s QOL.

Researchers in Germany assessed QOL among people who underwent surgery for thyroid cancer at University Hospital Mainz from 2010 to 2015. Eligible participants, all with low calcium and/or PTH levels following surgery, were interviewed at least one year after surgery.

QOL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and a EORTC QOL module for thyroid cancer. These are validated tools that measure QOL across different domains. For functional scales (such as physical abilities and emotional well-being), higher scores indicate fewer problems. For symptoms such as fatigue and pain, lower scores indicate fewer problems.

In total, the study included 75 people who underwent thyroid cancer surgery (mean age 49, mean time since surgery 3.8 years). Of these, 36 (48%) were taking long-term calcium and/or vitamin D supplements.

Compared to people not taking supplements, those who were reported significantly worse QOL scores for global health (mean score of 68.5 among those on supplements, and 76.7 among those not), physical functioning (89.3 vs. 95.7), joint pain (29.6 vs. 11.1), and role functioning (the ability to fulfill expected sociocultural roles, 77.3 vs. 89.3).

The scientists also compared QOL data of patients in this population with previously published QOL data on 2,028 individuals from the German population.

Patients showed a worse QOL than the general population in numerous domains, including fatigue (42.7% of patients), emotional functioning (33.3%), cognitive functioning (30.7%), pain (28.0%), insomnia (28.0%), difficulty breathing (26.7%), role functioning (26.7%), and social functioning (26.7%).

Additional analyses showed that, relative to people who did not take long-term supplements after surgery, those who did were 4.63 times more likely to score lower on role functioning than the general population. They were also 3.87 times more likely to have worse scores for emotional well-being.

This study suggests a connection between long-term calcium and vitamin D supplement use after thyroid cancer surgery and a poorer QOL later on.

A possible reason suggested by the researchers is that hypoparathyroidism may be more common among those taking supplements, although they could not assess permanent hypoparathyroidism during follow-up. If this is the case, low levels of PTH could contribute to the reduced QOL, with supplements not able to fully compensate for the hormone’s lack.

Another suggestion is that some patients may have been overtreated with calcium or vitamin D. “This might lead to short- or long-term complications of calcium or vitamin D intake, which leads to reduced QOL,” the investigators wrote.

Larger studies are needed to clarify the findings.

“Our study shows that patients more than 1 year post surgery who had early postoperatively low calcium or PTH levels report reduced QOL,” the researchers wrote. “Additionally, our study showed that almost half of the patients reported the intake of calcium or vitamin D and that intake was associated with higher odds for worse QOL in several domains.”

“Assessment of calcium and vitamin D and diagnosis of hypoparathyroidism are therefore important for the follow-up of thyroid cancer survivors since it may affect their QOL,” they added.