Serum 25-hydroxyvitamin D and health-related quality of life in patients with papillary thyroid carcinoma: a prospective cohort study.

BACKGROUND

The incidence of papillary thyroid carcinoma (PTC) is rising worldwide. Despite its excellent prognosis, many PTC patients experience impaired Health-Related quality of life (HRQoL). Vitamin D exerts pleiotropic effects on musculoskeletal, immune, and psychological health, but its impact on HRQoL in PTC patients remains unclear.

METHODS

This prospective cohort study consecutively recruited patients with PTC from January 2024 to August 2025. Baseline serum 25-hydroxyvitamin D concentrations were measured before treatment. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) and The Thyroid Cancer-Specific Quality of Life Questionnaire (THYCA-QoL) were applied to assess HRQoL. Associations between serum 25-hydroxyvitamin D and HRQoL domains were examined using rank-transformed general linear models, spearman correlation, multivariable linear regression and binary logistic regression. A nomogram was developed to predict the probability of weight gain in HRQoL domains and evaluated using Harrell's C-index and bootstrap calibration.

RESULTS

Among 600 patients, 27.8% had vitamin D deficiency, 69.5% had insufficiency, and 2.7% had sufficiency. Patients with sufficient vitamin D had better physical functioning and lower social functioning scores than those with deficiency or insufficiency (p = 0.002). Vitamin D was positively correlated with multiple functioning domains and negatively correlated with specific symptoms (all p < 0.05). In linear and logistic regression, higher vitamin D levels were independently associated with better physical and role functioning and fewer symptom burdens, and reduced the odds of impaired physical functioning (OR = 0.986, p = 0.016) and neuromuscular and weight gain symptoms (all p < 0.05). The nomogram showed fair discrimination (C-index 0.628) and good calibration.

CONCLUSION

Suboptimal vitamin D status was common among patients with PTC. Higher vitamin D levels were associated with better physical and role functioning and fewer neuromuscular, psychological, and weight gain symptoms. Assessment of vitamin D status may be considered as part of supportive care when clinically indicated.