Effects of vitamin D and calcium supplementation on side effects profile in patients of breast cancer treated with letrozole.

BACKGROUND

Vitamin D deficiency (<10ng/mL) and insufficiency (10-30ng/mL) may contribute to musculoskeletal symptoms observed in patients taking letrozole. This study was undertaken to assess the vitamin D status in breast cancer patients who received letrozole for >2months and to see the effects of vitamin D3 and calcium supplementation on them.

METHODS

Eighty-two breast cancer patients were included. Baseline serum 25-hydroxy vitamin D concentrations were assayed and standard questionnaire was completed. They were given vitamin D3 and calcium supplementation (2000IU/1000 mg and 4000IU/1000mg) based on their baseline serum 25-hydroxy vitamin D concentration for 12weeks.

RESULTS

Baseline serum 25-hydroxy vitamin D concentrations showed that 13.4% of patients were deficient and 73.2% of patients were insufficient in 25-hydroxy vitamin D. There was an increase in the concentrations of calcium, phosphorus and decrease in the concentrations of parathyroid hormone, alkaline phosphatase as the concentration of serum 25-hydroxy vitamin D increases. Patients who received letrozole for a longer duration had a low concentration of serum 25 (OH) vitamin D. Vitamin D3 and calcium supplementation increased the concentrations of calcium, phosphorous and decreased the concentrations of parathyroid hormone and alkaline phosphatase. Patients who had low serum 25-hydroxy vitamin D concentrations had more musculoskeletal symptoms which was improved following supplementation (9.14 vs 8.10 p=0.000).

CONCLUSION

Vitamin D3 supplementation significantly improved serum 25-hydroxy vitamin D concentrations and decreased letrozole-induced arthralgia.

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