Background & aims: Vitamin D impairs tumour-related transformation and supports the anticancer function of the immune system. Currently, there are no guidelines on vitamin D supplementation devoted solely to cancer patients. The primary objective of the study was to evaluate the frequency of vitamin D deficiency in Caucasian cancer patients and to characterize the clinical factors that predispose individuals to decreased vitamin D concentration. Secondly, the study aimed to estimate the dose of vitamin D supplementation that would prevent deficiencies in patients with cancer.
Methods: In the presented cross-sectional study the population consisted of 500 consecutive Caucasian patients with a diagnosis of neoplastic disease, some of which declared long-term vitamin D supplementation in various doses. Serum vitamin D concentration was measured once in all patients and clinical data were obtained from the hospital database. The frequencies of vitamin D deficiency were compared to certain clinical variables by appropriate statistical tests. The dose of vitamin D substitution in cancer patients was estimated using the receiver operating characteristic (ROC) curve.
Results: Vitamin D deficiency was diagnosed in 66.8% of patients with cancer and even in 31.6% who declared vitamin D supplementation. Older age, male gender, diagnosis of head and neck cancer or squamous cell carcinoma and body mass loss were identified as factors that predispose to vitamin D deficiency. The dose of vitamin D that would prevent deficiency in Caucasian patients with cancer was set at 2250 IU daily.
Conclusions: Vitamin D deficiency was very common in Caucasian patients with cancer, even in terms of vitamin D supplementation. The greatest predisposition was related to elder age, male gender, diagnosis of head and neck or squamous cell carcinoma and body mass loss. The dose of vitamin D supplementation in cancer patients should probably be higher than in the general population.
Keywords: Cancer; Dietary supplements; Recommendations; Vitamin D; Vitamin D deficiency; Weight loss.
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