Association between the Serum Vitamin D Concentration and All-Cause and Cancer-Specific Mortality in Individuals with Cancer.

We aimed to explore the association between the serum 25-hydroxyvitamin D concentration and all-cause and cancer-specific mortality in 2,463 adult patients with cancer from the National Health and Nutrition Examination Survey 2007-2018. We linked mortality data from the survey to the National Death Index records up to December 31, 2019. During a median follow-up period of 70 months, 567 patients died, of whom 194 died due to cancer. Multivariate adjustment was performed for demographic characteristics, lifestyle, dietary factors, 25-hydroxyvitamin D testing period, and cancer site. Higher serum 25-hydroxyvitamin D concentrations up to 75 nmol/L significantly reduced the risk of all-cause and cancer-specific mortality. When 25-hydroxyvitamin D quartiles were compared, the multivariable-adjusted hazard ratios were 0.59 (95% confidence interval: 0.42, 0.84) for all-cause mortality (P for trend <0.001) and 0.48 (95% confidence interval: 0.29, 0.79) for cancer-specific mortality (P for trend = 0.037) in quartile 3 (79.3-99.2 nmol/L). A threshold of 75 nmol/L for serum 25-hydroxyvitamin D may represent an intervention target to reduce mortalities in patients with cancer, and maintaining 25(OH)D concentrations within range (79.3-99.2 nmol/L) is beneficial for reducing all-cause and cancer-specific mortality.

An Analysis of Environment-, Individual-, and Tumor-Related Factors Impacting Hypovitaminosis D in Patients with Malignant Tumors.

Vitamin D (VD) plays a regulatory role in tumor occurrence and development, although the factors influencing serum 25-hydroxyvitamin D3 (25(OH)D3) levels in patients with cancer have not been studied. Therefore, we aimed to evaluate circulating levels of 25(OH)D3 and factors influencing the VD status in patients with malignant tumors. Adult patients with malignant tumors who had undergone assessments of serum 25(OH)D3 at Beijing Cancer Hospital from January 2019 to July 2022 were included. A multiple logistic regression model was applied to explore the associations of patient characteristics, environment, and disease characteristics with 25(OH)D3 levels. Among the 1,076 included patients, the median 25(OH)D3 serum concentration was 16.25 ng/mL. VD deficiency and the combined VD insufficiency and sufficiency were observed in 811 (75.37%) and 265 (24.63%) patients, respectively. Latitude, season, sex, body mass index, and type of cancer were associated with VD concentration/status in patients with malignant tumors. 25(OH)D3 concentrations were significantly higher in patients with thyroid cancer and significantly lower in patients receiving tumor-related treatment than in untreated patients. Surprisingly, we observed 25(OH)D3 serum concentration was lower in patients receiving nutritional supplementation than in those receiving no nutritional supplements. Patients with malignant tumors are at high risk of VD deficiency.