Study Reveals Vitamin D's Potential to Enhance Chemotherapy Efficacy in Breast Cancer Patients

A recent investigation by researchers at the Botucatu School of Medicine, part of São Paulo State University in Brazil, suggests that low-dose vitamin D supplementation may enhance the effectiveness of chemotherapy in women diagnosed with breast cancer. This finding opens up the possibility of using vitamin D as a more accessible alternative to certain pharmaceuticals that aim to improve chemotherapy responses.

The study involved 80 women over the age of 45, all preparing to begin chemotherapy at the oncology outpatient clinic of a teaching hospital. Participants were divided into two groups: one group received 2,000 international units (IU) of vitamin D daily, while the other was given placebo tablets. After six months of treatment, results indicated that 43% of the women who supplemented with vitamin D experienced a complete disappearance of their cancer, compared to only 24% in the placebo group. All participants underwent neoadjuvant chemotherapy, which is designed to shrink tumors before surgery.

Eduardo Carvalho-Pessoa, an author of the study published in the journal Nutrition and Cancer, remarked on the significant difference observed in treatment responses, despite the relatively small sample size. The dosage used in the study--2,000 IU daily--was notably lower than the typical corrective dosage for vitamin D deficiency, which is usually around 50,000 IU per week.

Vitamin D, a vital hormone for calcium and phosphorus absorption critical for bone health, has also been increasingly recognized for its role in bolstering the immune system, aiding in the fight against various diseases, including cancer. Most prior studies assessing the relationship between cancer and vitamin D supplementation had utilized higher doses of the vitamin.

Primarily obtained from sunlight exposure and dietary sources, the recommended daily intake of vitamin D is 600 IU for individuals not experiencing deficiency, and 800 IU for older adults. The American Academy of Pediatrics suggests a daily intake of 400 IU for infants. However, excessive vitamin D can lead to toxicity, resulting in symptoms such as nausea, weakness, bone discomfort, and kidney stones.

During the study, many participants exhibited low vitamin D levels, considered to be below 20 nanograms per milliliter (ng/mL) of blood. The Brazilian Society of Rheumatology advocates for optimal levels between 40 and 70 ng/mL. Carvalho-Pessoa noted that the supplementation led to an increase in vitamin D levels throughout the chemotherapy course, potentially contributing to the patients' recovery.

Additionally, he highlighted the advantages of vitamin D supplementation, as it is an affordable and easily accessible option in comparison to other drugs aimed at enhancing chemotherapy effectiveness, some of which are not available through Brazil's Unified Health System.

The promising findings of this study suggest a need for further research involving larger participant groups to better understand vitamin D's role in improving responses to chemotherapy and enhancing the likelihood of breast cancer remission.