Breast Pain and Vitamin D Deficiency

Abstract

In order to investigate the association of breast pain with vitamin D deficiency, serum levels of vitamin D were compared between women with and without mastalgia. Levels of vitamin D >75, 50-75, 25-50 and < 25 nmol/L were respectively considered as normal, mild, moderate and severe deficiency. There were 166 and 114 women in the case and control groups respectively. Final analysis showed that vitamin D deficiency was more frequent in the mastalgia group but the difference was not significant. We believe that further prospective studies are needed to clarify the subject.

Keywords: Breast pain; Mastalgia; Vitamin D deficiency

Introduction

While completing a clinical trial regarding effects of administration of vitamin D on mammographic density, we observed that several participants stated obvious decrease in their breast pain, which was not a study criterion in the trial. Therefore, we hypothesized that one of the etiologies of breast pain could be vitamin D deficiency. We had already performed a study assessing vitamin D levels in some breast pathologies and compared them with control groups [1]. In order to investigate the association of mastalgia with serum vitamin D levels, we retrospectively reviewed the breast clinic records about breast pain in the control group of the above study.

Methods

Participants had been selected among women attending the breast clinic of Arash Women’s Hospital, a university hospital affiliated to Tehran University of Medical Sciences, for breast cancer screening or any breast complaint. We retrospectively reviewed the breast clinic records of women who had normal breasts in physical exam and imaging and whose serum vitamin D levels had been measured in our hospital during the last year. Exclusion criteria included chronic illness, history of cancer, pregnancy or lactation, malabsorption syndrome or gastric disorders, metabolic bone disease, renal or hepatic failure, recent history of therapeutic vitamin D consumption or osteoporosis treatment. Breast exam had been carried out by one of two breast surgeons in the clinic, mammography had been performed for all women above 40 years of age; and ultrasonography as indicated by the radiologist or the breast surgeon in this age group, and in all patients less than 40 years of age. Women who had complained of breast pain as recorded in datasheets were considered as the Case or Mastalgia group and those without pain as the Control or Normal Group. Exclusion criteria consisted of consumption of any form of Vitamin D supplement in the last two years, recent treatment of osteopenia or osteoporosis, and history of any cancer or renal failure.

A 2 milliliters sample of blood had been taken by a laboratory technician from all the participants and refrigerated in -40 degrees centigrade for less than one month. Levels of vitamin D had been measured by the electrochemiluminescense method (Roche, Cobas e411, Germany) in all samples in the hospital laboratory.

Serum levels >75 and =75 nannomole per liter (nmol/L) were respectively considered normal and deficient. Degree of vitamin D deficiency was classified as mild deficiency in levels between 50 and 75 nmol/L, moderate deficiency if from 25 to 50 nmol/L and severe deficiency when serum levels were less than 25 nmol/L [2]. In this case-control study, we used simple logistic regression to assess the association between deficient or insufficient vitamin D levels — the exposure or independent variable — and the likelihood of having mastalgia — the outcome or dependent variable, among participants. We then used multiple logistic regression to assess the relationship after controlling for age as covariate; SPSS^® 16.0 software (SPSS Inc., Chicago, IL, USA) was used for analyzing data. P. value <0.05 was considered significant.

Results and Discussion

Among the 316 women who could have been enrolled in the study, 284 had answered to the question about breast pain. From these, 166 had breast pain and were included as the case group, and 114 had no pain and constituted the control group. Age range was 42.89 ± 12 years overall, and 42.19 ± 11 years in the case and 46.6 ± 9 years in the control group. Numbers of patients with normal and low levels of vitamin D and those in each subgroup of vitamin D deficiency regarding mastalgia

  

    
Mastalgia
    
Vitamin D status
  
  

    
Normal*
      
Number (percent)
    
Deficiency** 
      
Number (percent)
  
  

    
Mild*
    
Moderate**
    
Severe***
    
All
  
  

    
No
    
45 (39.5%)
    
5 (4.4%)
    
13 (11.4%)
    
51 (44.7%)
    
69 (60.5%)
  
  

    
Yes
    
50 (30.1%)
    
13(7.8%)
    
24 (14.5%)
    
79 (47.6%)
    
116 (69.9%)
  
  

    
Total
    
95 (33.9%)
    
18 (6.4%)
    
37 (13.2%)
    
130 (46.4%)
    
185 (66.1%)
  
  

    
Serum vitamin    D: * >75 nmol/L, ** =75 nmol/L, * =    50-75 nmol/L, ** = 25-50 nmol/L, *** < 25 nmol/L
      
 
  

Table 1:  Mastalgia status in normal and deficient levels of vitamin D.