Does Vitamin D Prevent Breast Cancer Reoccurrence and Mortality? As Vitamin D deficiency becomes so prominent amongst many people and there is an abundance of cases where breast cancer reoccurs or leads to mortality, research presented in The Journal of the American Medical Association suggests that there may be a correlation between the two. Vitamin D has an important role in the body, some of which include: modulation of cell growth, neuromuscular and immune function, reducing inflammation, absorbing calcium and assists muscle and nervous systems in functioning properly. However, since it is not found in significant quantities of food and exposure to sunlight is limited in certain parts of the world, people often are deficient in vitamin D. Moreover, the variety of roles that come from one vitamin becomes immensely important when trying to fight off cancer. Research suggests that women with lower levels of vitamin D are at a higher risk of developing breast cancer, as it controls the growth of breast cells and irregular production of cells. To support this, Yao et al., conducted a cohort study in 2016 of 1666 newly diagnosed women with breast cancer in North Carolina. Participants were followed for 5 years and interviewed at a 12-month interval. Tests on the participants mostly included baseline interviews, anthropometric measures such as, height, weight, BMI, body fat percentage and blood samples, which were collected 69 days after diagnosis. The mean age of the participants in this study was approximately 58.7 years. The purpose of this study was to investigate how a serum level of vitamin D, 25-hydroxyvitamin D (25OHD) reacted to different stages of breast cancer, where racial and nonclinical factors such as BMI, height, socioeconomic status, physical activity and smoking were taken into consideration. The results presented by Yao et al. from this case-cohort state that higher serum 25OHD levels were independently connected with better outcomes, including overall survival. In addition, serum 25OHD concentrations were lower in women with advanced-stage tumors and the lowest in premenopausal women with triple-negative cancer. Therefore, women with higher levels of 25OHD levels and premenopausal women had a higher overall survival. However, some factors altered these results and it was established that based on race, African Americans and Hispanics had lower 25OHD concentrations than Caucasians, and current smokers had lower concentrations than those who never smoked or used to previously smoke. These findings are important because it provides data and hypotheses that are not abundant in medical research and journals, because it is hard to measure and provide evidence that both variables, vitamin D and breast cancer mortality and reoccurrence, are correlated. Hence, the data and conclusion to this study should be taken with caution as other factors could affect 25OHD levels. Additional imprecisions could be due to blood samples collected 69 days after diagnosis, where some of the women had already begun chemotherapy causing hormonal and nutrient levels to change. Another inaccuracy that contributes to the limitations of this study was, because the cohort was so large, it would be difficult to determine the cause of death or reoccurrence of cancer resulting in unquestionable evidence of if vitamin D levels were linked to preventing breast cancer. In contrary, the strengths of these findings were including different racial groups in this study to represent that people with darker skin have melanin (a pigment in the skin) resulting in less vitamin D that absorbs into the body and having a case-cohort study that followed the participants over a long period. This helps to provide more accurate results to see if there was a reoccurrence of breast cancer and to determine the reason behind mortality in these women. In conclusion, this study should be taken with caution and should be researched further. However, it does provide the idea of vitamin D being a good preventative measure and a natural source for the body to help reduce cancer cells and possibly prevent reoccurrence. source
