Obesity and cancer: the role of vitamin D

Abstract

BackgroundIt is estimated that 20% of all cancer cases are caused by obesity. Vitamin D is thought to be one of the mechanisms underlying this association. This review aims to summarise the evidence for the mediating effect of vitamin D on the link between obesity and cancer.MethodsThree literature searches using PubMed and Embase were conducted to assess whether vitamin D plays an important role in the pathway between obesity and cancer: (1) obesity and cancer; (2) obesity and vitamin D; and (3) vitamin D and cancer. A systematic review was performed for (1) and (3), whereas a meta-analysis including random effects analyses was performed for (2).Results(1) 32 meta-analyses on obesity and cancer were identified; the majority reported a positive association between obesity and risk of cancer. (2) Our meta-analysis included 12 original studies showing a pooled relative risk of 1.52 (95% CI: 1.33-1.73) for risk of vitamin D deficiency (<50 nmol/L) in obese people (body mass index >30 kg/m2). (3) 21 meta-analyses on circulating vitamin D levels and cancer risk were identified with different results for different types of cancer.ConclusionThere is consistent evidence for a link between obesity and cancer as well as obesity and low vitamin D. However, it seems like the significance of the mediating role of vitamin D in the biological pathways linking obesity and cancer is low. There is a need for a study including all three components while dealing with bias related to dietary supplements and vitamin D receptor polymorphisms.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2407-14-712) contains supplementary material, which is available to authorized users.

The Pleiotropic Effects of Vitamin D in Gynaecological and Obstetric Diseases: An Overview on a Hot Topic

“…Of particular interest in this regard, it is estimated that 20% of all cancer cases are caused by obesity in women [ 110 ] and vitamin D is thought to be one of the mechanisms underlying this association. Shanmugalingam et al [ 111 ] performed a systematic review and meta-analysis in order to assess whether vitamin D plays a role in the pathway between obesity and cancer, since no mediation analyses have been performed for this effect to date. For the topic obesity and cancer, a positive association was reported between obesity and risk of cancer, showing that the strength of this association varies between cancer sites, sex, and, in breast cancer, the menopausal status.…”

“…The most likely hypothesis is that vitamin D stored in fat tissue increases local vitamin D concentrations causing activation of the VDR in adipocytes. This may lead to low energy usage and further promotion of obesity [ 111 , 113 ]. Finally, authors evaluated if vitamin D is a mediator for the association between obesity and cancer.…”

Safety and Efficacy of Banaba–Moringa oleifera–Green Coffee Bean Extracts and Vitamin D3 in a Sustained Release Weight Management Supplement

“…The tablet also contains 500 IU of vitamin D. Vitamin D deficiency occurs in a majority of people in the United States. Many studies have reported an association between vitamin D and adipose tissue metabolism as well as the possible role of low levels of vitamin D in obesity (Cipriani et al, 2014;Shanmugalingam et al, 2014). Decreases in the BMI and FM have also been shown to occur in conjunction with vitamin D supplementation (Pathak et al, 2014).…”

Vitamin D and cancer; a contradictory problem

“…Moreover, enough intake of vitamin D could have a beneficial influence on some cancers (6) such as cancers of colon (7), breast (8), prostate (9), pancreatic (10) and ovarian (11). Nowadays, there is a pandemic of obesity worldwide (12) and almost one-fifth of all cancers might cause by obesity (13). There is a relationship between obesity and low intake of vitamin D (13).…”