High prevalence of vitamin D deficiency despite supplementation in premenopausal women with breast cancer undergoing adjuvant chemotherapy.
OBJECTIVE
Vitamin D deficiency is associated with increased breast cancer risk and decreased breast cancer survival. The purpose of this study was to determine the prevalence of vitamin D deficiency, as measured by serum 25-hydroxyvitamin D (25-OHD), in premenopausal women at initiation of adjuvant chemotherapy for breast cancer and after 1 year of vitamin D supplementation.


METHODS
The study included 103 premenopausal women from the northeastern United States with stages I to III breast cancer who received adjuvant chemotherapy and participated in a 1-year zoledronate intervention trial. All patients were prescribed vitamin D(3) (cholecalciferol) 400 IU and calcium carbonate 1,000 mg daily. At baseline and at 6 and 12 months, bone mineral density (BMD) measurements were obtained and blood was collected and analyzed in batches for serum 25-OHD. Vitamin D deficiency was defined as serum 25-OHD less than 20 ng/mL, insufficiency as 20 to 29 ng/mL, and sufficiency as 30 ng/mL or greater.


RESULTS
At baseline, 74% of women were vitamin D deficient (median, 17 ng/mL). Vitamin D deficiency was slightly less common in white women (66%) compared with black (80%) and Hispanic (84%) women. After vitamin D supplementation for 1 year, less than 15% of white and Hispanic women, and no black women, achieved sufficient 25-OHD levels. Vitamin D levels did not correlate with baseline BMD and were not altered by chemotherapy or bisphosphonate use.


CONCLUSIONS
Vitamin D deficiency is highly prevalent in women with breast cancer. The current recommended dietary allowance of vitamin D is too low to increase serum 25-OHD greater than 30 ng/mL. Optimal dosing for bone health and, possibly, improved survival has yet to be determined.
Crew
Katherine D
KD
Department of Medicine, Division of Oncology, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
Shane
Elizabeth
E
Cremers
Serge
S
McMahon
Donald J
DJ
Irani
Dinaz
D
Hershman
Dawn L
DL
D000328:Adult; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008875:Middle Aged; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
D014807:Vitamin D; C104450:25-hydroxyvitamin D