Vitamin D concentrations and breast cancer incidence among Black/African American and non‐Black Hispanic/Latina women

Abstract

Background Vitamin D may protect against breast cancer. Although Black/African American women and Hispanic/Latina women have lower circulating vitamin D levels than non‐Hispanic White women, few studies have examined the association between vitamin D and breast cancer within these racial/ethnic groups. Methods The vitamin D–breast cancer association was evaluated using a case‐cohort sample of self‐identified Black/African American and non‐Black Hispanic/Latina women participating in the US‐wide Sister Study cohort. Circulating 25‐hydroxyvitamin D (25(OH)D) and 24,25‐dihydroxyvitamin D (24,25(OH)2D) were measured using liquid chromatography‐tandem mass spectrometry in blood samples collected at the baseline from 415 women (290 Black/African American women and 125 non‐Black Hispanic/Latina women) who developed breast cancer. These were compared to concentrations in 1545 women (1084 Black/African American women and 461 Hispanic/Latina women) randomly selected from the cohort. Multivariable‐adjusted Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results Over a mean follow‐up of 9.2 years, women with circulating 25(OH)D concentrations above the clinical cut point for deficiency (20.0 ng/mL) had lower breast cancer rates than women with concentrations ≤ 20 ng/mL (HR, 0.79; 95% CI, 0.61‐1.02). The inverse association was strongest among Hispanic/Latina women (HR, 0.52; 95% CI, 0.29‐0.93), with a weaker association observed among Black/African American women (HR, 0.89; 95% CI, 0.68‐1.18; P for heterogeneity = 0.13). There were no clear differences by menopausal status, follow‐up time, estrogen receptor status, or invasiveness. Neither 24,25(OH)2D nor the 24,25(OH)2D to 25(OH)D ratio were independently associated with breast cancer risk. Conclusions This prospective study supports the hypothesis that vitamin D may be protective against breast cancer incidence in women, including non‐Black Hispanic/Latina and Black/African American women. LAY SUMMARY Vitamin D may protect against breast cancer. Although women of color have lower average vitamin D levels than non‐Hispanic White women, few studies have considered the role of race/ethnicity. In a sample of self‐identified Black/African American and Hispanic/Latina women, we observed that vitamin D concentrations measured in blood were inversely associated with breast cancer, particularly among Latinas. These findings indicate that vitamin D may protect women against breast cancer, including those in racial/ethnic groups with low average circulating levels.

The Impact of Vitamin D and Its Dietary Supplementation in Breast Cancer Prevention: An Integrative Review

“…Table 4 includes a set of five articles [ 88 , 89 , 90 , 91 , 92 , 93 ] aimed at elucidating various potential factors that may influence the relationship between vitamin D levels and BC. Various factors related to vitamin D and its influence on the risk of BC have been discussed, such as lifestyle [ 88 ], calcium [ 89 ], and epigenetics [ 90 ].…”

Vitamin D and breast cancer: Stop torturing the data!

“…Lastly, insulin resistance and Type 2 diabetes, which also affect the vitamin D status, were not tested. 4 Third, the confidence intervals for the hazard ratios include 1 and, therefore, are not significant (see Tables 2-4 in O'Brien et al 1 ) Furthermore, hazard ratios are rarely appropriate and are frequently misinterpreted: Their direction can be used to explain the direction of the relative risk, but the magnitude is not related to the relative risk, which, being much higher and more impressive than its absolute counterpart, is not appropriate for clinical decisions. Notably, an adequately sized series (231,203 women in the UK Biobank cohort) also failed to provide evidence for an association between vitamin D and ductal carcinoma in situ, 5 and a Mendelian randomization analysis comprising 15,748 breast cancer cases did not support a causal effect of 25(OH)D concentrations.…”

“…O'Brien and colleagues' post hoc analysis of a short series of 6857 women from the Sister Study cohort, which concluded that "findings add to the evidence that vitamin D protects against breast cancer and highlight a possible path for intervention in 2 racial/ethnic groups," deserves robust comment. 1 First, post hoc analysis is only about hypothesis generation, and the study does not conform to reporting guidelines. Preregistration is one of the many quality requirements of the Strengthening the Reporting of Observational Studies in Epidemiology guidelines, whose endorsement is recalled in the journal's instructions for authors.…”

Reply to “Vitamin D and breast cancer: Stop torturing the data!”

“…We are writing in response to the letter from Alain Braillon in reference to our article entitled “Vitamin D Concentrations and Breast Cancer Incidence Among Black/African American and Non‐Black Hispanic/Latina Women.” 1 …”

“…We are writing in response to the letter from Alain Braillon in reference to our article entitled "Vitamin D Concentrations and Breast Cancer Incidence Among Black/African American and Non-Black Hispanic/Latina Women." 1 We have fully adhered to the ethical requirements of the Strengthening the Reporting of Observational Studies in Epidemiology guidelines 2 and the journal. The Sister Study is registered at Clini calTr ials.gov (NCT00047970) and has an internal tracking system in which analysis plans are approved and posted (https://www.siste rstud ystars.…”