Changes in Circulating Levels of 25-hydroxyvitamin D3 in Breast Cancer Patients Receiving Chemotherapy

Abstract

Cancer treatments, toxicities and their effects on lifestyle, may impact levels of vitamin D. The aim of this study was to determine serum 25-hydroxyvitamin D3 (25(OH)D 3) levels before, directly after and 6 months after chemotherapy in breast cancer patients (n ¼ 95), and a comparison group of women (n ¼ 52) not diagnosed with cancer. Changes in 25(OH)D 3 levels over time were compared using linear mixed models adjusted for age and season of blood sampling. Before start of chemotherapy, 25(OH)D 3 levels were lower in patients (estimated marginal mean 55.8 nmol/L, 95% confidence interval (95%CI) 51.2-60.4) compared to the comparison group (67.2 nmol/L, 95%CI 61.1-73.3, P ¼ 0.003). Directly after chemotherapy, 25(OH)D 3 levels were slightly decreased (-5.1 nmol/L, 95%CI-10.7-0.5, P ¼ 0.082), but ended up higher 6 months after chemotherapy (10.9 nmol/L, 95%CI 5.5-16.4, P < 0.001) compared to pre-chemotherapy values. In women without cancer, 25(OH)D 3 levels remained stable throughout the study. Use of dietary supplements did not explain recovery of 25(OH)D 3 levels after chemotherapy. We reported lower 25(OH)D 3 levels in breast cancer patients, which decreased during chemotherapy, but recovered to levels observed in women without cancer within 6 months after chemotherapy. Suboptimal 25(OH)D 3 levels in the majority of the participants highlight the relevance of monitoring in this vulnerable population.

Circulating Vitamin D Levels and DNA Repair Capacity in Four Molecular Subtypes of Women with Breast Cancer

“…In our study, the blood collection was performed at the time of diagnosis which allowed us to avoid any confounding effects due to BC treatment. As previously reported, BC therapy can alter plasma vitamin D levels [47,48]. It has been reported that after 6 months of chemotherapy, vitamin D levels can be reduced to almost 5.52 ng/mL (p = 0.003).…”

A Phase II Multicenter Trial on High-Dose Vitamin D Supplementation for the Correction of Vitamin D Insufficiency in Patients with Breast Cancer Receiving Adjuvant Chemotherapy

“…This value is even lower than the percentage of patients with VD insufficiency on D1C6, although only 36% of patients were still taking VD supplementation at month 24 of follow-up. This could be partly explained by previous studies showing a decrease in 25-OH VD concentration during chemotherapy and a recovery after treatment end [27][28][29]. It has been suggested that taxanes, corticosteroids, behavioral changes (such as sunlight exposure, dietary intake), and gastrointestinal side-effects play a role in this initial decrease in 25-OH VD levels [27][28][29][30].…”

“…This could be partly explained by previous studies showing a decrease in 25-OH VD concentration during chemotherapy and a recovery after treatment end [27][28][29]. It has been suggested that taxanes, corticosteroids, behavioral changes (such as sunlight exposure, dietary intake), and gastrointestinal side-effects play a role in this initial decrease in 25-OH VD levels [27][28][29][30]. This could explain the important 25-OH VD concentration decrease at month 12 of follow-up (only 28.9% of patients with normalized 25-OH VD level).…”

Prevalence and Relevance of Vitamin D Deficiency in Newly Diagnosed Breast Cancer Patients: A Pilot Study

“…In the present study, all patients received blood sampling at the time of diagnosis and prior to the start of treatment. In particular, patients with aggressive (e.g., triple negative carcinomas) or advanced tumor stages (cT3/4, cN+) were treated with (neo-) adjuvant chemotherapy, and it is well known that chemotherapy can lead to decreased 25(OH)D levels [ 50 , 51 , 52 ]. In the cited studies [ 48 , 49 ], the time of 25(OH)D level determination was very heterogenous.…”