Evaluation of breast cancer in Iranian women in an ecological study based on latitude, sun exposure and vitamin D intake

Document Type : Original Article


1 M.Sc. student of Epidemiology, School of public health, Hamadan University of Medical Sciences, Hamadan, Iran.

2 Associate Professor, Department of Epidemiology, School of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.

3 PhD student of Epidemiology, Department of Epidemiology, School of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

4 Internist, Clinical Research Development Center, Imam khomaini Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran.


Introduction: Breast cancer is the most common cancer and the major factor of death from cancer in women worldwide and also it is the most common cancer among women in Iran. Many studies suggest that breast cancer is associated with latitude, sunlight and vitamin D. This study was conducted with aim to ecologically evaluate breast cancer in Iranian women based on geographical latitude, exposure to sunlight and vitamin D.
Methods: This ecological study is was performed in 2014 with aim to evaluate the relationship between breast cancer in Iranian women and some effective factors such as latitude, exposure to sunlight and vitamin D. For this purpose, we used National Cancer Registry data, Iran segmentation map based on latitude, distribution of prevalence of vitamin D deficiency based on the results of the study of SaeidNia, and mean hours of sunlight which was collected by the Meteorological Agency.
Results: in lower latitudes especially at 20 to25 degrees which the incidence of breast cancer is lower, the prevalence of vitamin D deficiency is lower and mean hours of sunlight is higher than higher latitudes.
Conclusion: There is negative association between the incidence of breast cancer, latitude, hours of exposure to sunlight and vitamin D intake. However, analytical studies will be needed to achieve scientific inferences.


1.     Ghyasvand R. Epidemiology of breast cancer. Cancer Research Center Cancer Institute of IR Iran.2-18.
2.     Walentowicz-Sadłecka M, Sadłecki P, Walentowicz P, Grabiec M. The role of vitamin D in the carcinogenesis of breast and ovarian cancer. Ginekologia polska 2013;84(4):305-8.
3.     Oh E-Y, Ansell C, Nawaz H, Yang C-H, Wood PA, Hrushesky WJ. Global breast cancer seasonality. Breast cancer research and treatment 2010;123(1):233-43.
4.     Kulie T, Groff A, Redmer J, Hounshell J, Schrager S. Vitamin D: an evidence-based review. The Journal of the American Board of Family Medicine 2009;22(6):698-706.

5.     Hagenau T,Vest R, Gissel TN, Poulsen CS, Er-landsen M, Mosekilde L,Vestergaard PG. Global vitamin D levels in relation to age, gender, skin pigmentation and latitude: an ecologic meta-regression analysis.Osteopo-ros Int 2009; 20(1): 133-40.

6.     Holick, M, Chen TC. Vitamin D deficiency: a world-wide problem with health consequences. American Journal of Clinical Nutrition 2008; 87: 7.
7.     Holick MF,Vitamin D: importanceinthe prevention of cancers, type 1 diabetes, heart disease, and osteoporosis.AmJClinNutr 2004; 79(3): 362-71.
8.     Hernan MA, Olek MJ, Ascherio A. Geographic variation of MS incidence in two prospective studies of US women. Neurology 1999; 53(8): 1711-8.
9.     Holick MF.Sunlightand vitamin D for bone health and prevention of auto immune dis-eases,cancers, and cardiovascular disease. Am J Clin Nutr 2004; 80: 11.
10.   Heshmat R, Mohammad K, Majdzadeh SR, Forouzanfar MH, Bahrami A, Ranjbar GH, Omrani N, Rajabian R, Hossein-Nezhad A, Rezaei Hemami M, Keshtkar AA, Pajouhi M,  Larijani B. Vitamin D Deficiency in Iran: A Multi-center Study among Different Urban Areas. Iranian J Publ Health 2010; 39(3): 45-52.
11.   Mithal A, Wahl DA, Bonjour JP, Burckhardt P, Dawson-Hughes B, Eisman JA, et al. Committee of Scientific Advisors (CSA) Nutri-tion Working Group. Global vitamin D status and determinants of hypovitaminosis D. Os-teoporos Int 2009; 20(11):1807-2019.
12.   Aghajani H, et al. Iranian Annual of National Cancer Registration Report. IRI Ministry of Health and Medical Education Health and Treatment Deputy Tehran: Tandis; 2008-2009.
14.   Saeedi Nia A, Larijani B, Jalali Nia SH. Investigate the prevalence of vitamin D deficiency in Iranian population living inthe Islamic Republic of Iran to the breakdown provinces in the period 1990 to 2010. Iranian Journal of Diabetes and Lipid disorders 2013;12(6):574-84. [Persian].
15.   Grant WB. An ecological study of cancer incidence and mortality rates in France with respect to latitude, anindex for vitamin D production. Dermatoendocrinol 2010;2(2):62-7.
16.   Stephanie L H,  Keels S J, Kristine M T. Breast cancer survivo rs and vitamin D: A review. Nutrition 2010;26(3):255-62.
17.   Borisenkov MF. Latitude of residence and position in time zone are predictors of cancer incidence, cancer mortality, and life expectancy at birth. Chronobiol Int 2011; 28(2):155-62.
18.   Holick MF. Vitamin D and sunlight: strategies for cancer prevention and other health benefits. Clin J Am Soc of Nephrol 2008;3(5):1548-54.
19.   Yousef FM, Jacobs ET, Kang PT, Hakim IA, Going S, Yousef JM, et al. Vitamin D status and breast cancer in Saudi Arabian women: case-control study. The American journal of clinical nutrition 2013; 98(1):105-10.
20.   van der Rhee H, Coomans C, van de Velde P, Coebergh J, de Vries E. Illness, health and sunlight. Nederlands tijdschrift voor geneeskunde 2012;157(46):A6612-.
21.   Engel LS, Satagopan J, Sima CS, Orlow I, Mujumdar U, Coble J, et al. Sun Exposure, Vitamin D Receptor Genetic Variants, and Risk of Breast Cancer in the Agricultural Health Study. Environ Health Perspect 2014; 12(2):165-71.
22.   Erren TC, Koch MS, Gross JV, Reiter RJ, Meyer-Rochow VB. A possible role of perinatal light in mood disorders and internal cancers: reconciliation of instability and latitude concepts. Neuro Endocrinol Lett 2012; 33(3):314-7.
23.           Wu S-H, Ho SC, So E, Lam T-p, Woo J, Yuen P, et al. Sunlight Exposure and Breast Density: A Population-Based Study. Journal of breast cancer 2013;16(2):171-7.