New research suggests that patients who have insufficient levels of vitamin D before starting paclitaxel treatment are more likely to experience peripheral neuropathy. According to an analysis of 1,191 patients with early-stage breast cancer—using data collected in the SWOG S0221 study—20.7% of patients with vitamin D deficiency experienced at least a grade 3 level of chemotherapy-induced peripheral neuropathy (CIPN), compared to 14.2% of those with sufficient vitamin D levels. The researchers also found that inducing vitamin D deficiency in an accompanying mice model study caused neurotoxicity-like symptoms. "These results suggest that vitamin D supplementation in patients with lower levels of...