The results of a new study find that a laboratory-altered form Study Shows that Vitamin D May Aid in Breast Cancer Treatment (dateline September 30, 2003) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Study Shows that Vitamin D May Aid in Breast Cancer Treatment (dateline September 30, 2003)

The results of a new study find that a laboratory-altered form of vitamin D, combined with radiation therapy, may help in the treatment of patients with breast cancer. In the preliminary study conducted on mice, those who received the vitamin D in addition to radiation had 50% smaller breast cancer tumors after treatment, compared to the mice who did not receive the vitamin D. While the results of the study are promising, the researchers warn that the vitamin D derivative used in the study is not equivalent to over-the-counter vitamin D supplements and that taking large amounts of those vitamins may be harmful.

In the study, Andrea Sea of Dartmouth Medical School and colleagues injected some mice with a laboratory-altered form of vitamin D while others received a placebo (inactive substance). A total of eight mice were used in the study. The mice been previously infected with breast cancer and each received radiation as treatment, with or without the vitamin D. They were then monitored for 25 to 30 days after the treatment period.

The results showed that the mice who received the vitamin D compound had a significant reduction in the size of their breast cancer tumors compared to the mice who did not receive vitamin D. After the follow-up period, the tumors were 50% smaller in the mice who received vitamin D. Furthermore, the vitamin D compound stunted the growth of additional cancer cells during the treatment period.

Thus, this small, preliminary study shows the potential for a vitamin D-developed compound to aid in the treatment of breast cancer. In the study, vitamin D had to be altered in the laboratory to eliminate the potentially toxic side effects that such a large dose could cause on its own (namely, hypercalcaemia—an overdose of calcium). Further studies will likely continue to investigate the potentially beneficial role of vitamin D in breast cancer treatment.

Interestingly, previous research has shown that women who have genetic variations that prevent their bodies from making use of vitamin D may be at greater risk of developing breast cancer than women without these genetic abnormalities. However, this research is also in preliminary stages and needs further confirmation in larger studies.

With the increased popularity of vitamin and mineral supplements, several other studies have investigated the effects of vitamins on breast cancer risk. A study conducted at the Istituto Nazionale Tumori in Milan, Italy showed that fenretinide, a non-toxic drug related to Vitamin A, may reduce the chances of recurrent (returning) breast cancer in pre-menopausal women. Breast cancer patients are encouraged to check with their doctors before taking dietary supplements.

In the meantime, the standard breast cancer treatment is surgery; the type (lumpectomy, mastectomy, etc.) depends on the tumor size and a host of other factors, including a patient’s individual medical profile. Additional treatments, typically used in conjunction with surgery, include chemotherapy, radiation, or other drugs, such as tamoxifen.

Additional Resources and References

  • The report, "The Combination of a Potent Vitamin D3 Analog, EB 1089, with Ionizing Radiation Reduces Tumor Growth and Induces Apoptosis of MCF-7 Breast Tumor Xenografts in Nude Mice," is published in the June issue of the Journal of Clinical Cancer Research,