Vitamin D relieves pain induced by aromatase inhibitors in breast cancer patients

Vitamin D relieves pain induced by aromatase inhibitors in breast cancer patients

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Editor's note: We are the first news outlet in the world to report this study.

By David Liu, Ph.D.

Tuesday July 26, 2011 (foodconsumer.org) -- Taking high doses of vitamin d2 may help breast cancer patients to reduce joint and muscle pain or musculoskeletal symptoms associated with use of aromatase inhibitors, according to a new trial led by researchers at Washington University School of Medicine in St. Louis.

Aromatase inhibitors are given breast cancer patients whose diseases are in an early stage to lower estrogen and prevent recurrence of the disease. These drugs are not as toxic as chemotherapy drugs, but they do induce pain in many loci in the body for unknown reasons.

Vitamin d has been associated with reduced risk of breast cancer.  Some studies suggest that taking high doses of vitamin D or exposure to sufficient sunlight may prevent as many as 70 percent of breast cancer cases.

The current study of sixty breast cancer patients was intended to investigate the effect of vitamin d2, which is derived from plant sources and more easily metabolized, on pain and bone loss associated with use of anastrozole one of the aromatase inhibitors approved by the Food and Drug Administration.

For the phase II trial, Dr. Antonella L. Rastelli and colleagues run two studies. In one study, they gave patients with 20-29 ng per ml of 25-hydroxy vitamin D (25OHD) in their blood 50,000 IU of vitamin d2 capsule per week  for eight weeks and then monthly for four months or placebo.

In another study, the researchers gave breast cancer patients with 10-19 ng per ml of vitamin D in their blood vitamin D supplements for 16 weeks and then monthly for two months or placebo.

All patients were given 1,000 milligrams of calcium daily.

The intensity of pain was assessed at baseline, two, four and six months and bone mass density was measured at baseline, and six months.

Vitamin D  supplementation was associated with reduced pain.  The effect of vitamin d2 on bone mass density was strong, particularly in those with low levels of vitamin D at baseline.

Bone mass density at the femoral neck was found decreased among breast cancer patients on the placebo and no change in BMD was found in those who were on the vitamin d2 supplement. 

The researchers used vitamin D2 instead of vitamin d3 because it takes only 7 to 10 days for the body to metabolize vitamin d2. Because of this, vitamin d2 is safer, compared with vitamin d3.

The study was published in the Aug 2011 issue of Breast Cancer Research and Treatment.