Abstract
•There is a paucity of research on vitamin D and breast cancer in Saudi Arabia.•We are the first to study vitamin D and breast cancer characteristics in Saudi Arabia and even in the Middle East.•In a population where the prevalence of vitamin D deficiency [25 (OH) D level below 50nmol/L] ranges between 68% and 85%, we found that 71% of breast cancer patients were vitamin D deficient.•Triple negative disease was significantly associated with vitamin D level below 25nmol/L.
Inverse relationship between vitamin D status and risk of breast cancer has been previously reported in the literature. We conducted this study to determine the association between vitamin D levels and breast cancer characteristics in patients from Saudi Arabia.
Newly diagnosed breast cancer patients (N=406) were recruited. Serum levels of 25-hydroxyvitamin D [25 (OH) D] were measured at baseline.
A significantly higher percentage of patients with triple negative status (18%) had 25 (OH) D levels ≤25nmol/L, compared to only 8% with 25 (OH) D levels >25nmol/L (p=0.009). Patients with 25 (OH) D levels ≤25nmol/L were 2.54 times more likely to present with triple negative status compared to those with 25 (OH) D levels >25nmol/L (p=0.02).
Our findings suggest an association between low 25 (OH) D levels and increased risk of triple negative breast cancer.