Dietary Intake, Supplement Use, and Survival Among Women Diagnosed With Early-Stage Breast Cancer

Abstract

Previous studies examining the relationship between micronutrient intakes and survival following diagnosis of breast cancer have reported mixed results. This may be partly due to considerable variance in amounts of micronutrients consumed from diet and supplements across studies. Early-stage breast cancer survivors (N = 3081) completed four 24-h dietary and supplement recalls at the baseline assessment (1995 to 2000) and were followed for a median of 9.0 yr. Mean micronutrient intakes were compared to dietary reference intakes (DRI) to assess micronutrient adequacy for both users and nonusers of supplements. Cox regressions were performed to assess whether intakes of selected micronutrients were associated with all-cause mortality. Four hundred and twelve deaths occurred between baseline and August 2009. Among these women, more supplement users had adequate micronutrient intakes than nonusers for 15 out of 17 micronutrients. Less than 10% of supplement users (<2% of nonsupplement users) reported levels that exceeded the tolerable upper limit for each micronutrient except magnesium. After adjusting for age, tumor characteristics, and health status variables, micronutrient intakes were not significantly associated with all-cause mortality. Dietary supplements may improve overall micronutrient intakes of breast cancer survivors. However, vitamin and mineral intakes were not associated with all-cause mortality.