Researchers in Brazil have found that a simple vitamin D supplement may help chemotherapy work better in women with breast cancer. The study, carried out at the Botucatu School of Medicine at São Paulo State University (FMB-UNESP), suggests that low doses of the vitamin could improve treatment outcomes and potentially serve as a more accessible option compared to certain expensive or hard-to-obtain drugs designed to enhance chemotherapy response. The research, funded by FAPESP, included 80 women over the age of 45 who were preparing to begin treatment at the oncology outpatient clinic of the general and teaching hospital ("Hospital das Clínicas") at FMB-UNESP. Participants were split into two equal groups. One group received a daily dose of 2,000 IU (international units) of vitamin D, while the other group was given placebo tablets. All of the women underwent neoadjuvant chemotherapy, a treatment given before surgery to shrink tumors and make them easier to remove.…