Most recent update: Tuesday, May 23, 2017 - 15:27

Bariatric News - Cookies & privacy policy

You are here

Vitamin D

Obesity, cancer and vitamin D deficiency

There was a consistent positive association between obesity and cancer with relative risks varying between 1.10 and 1.90 when addressing the existing literature
The literature for vitamin D status and cancer risk only showed consistent evidence for an inverse association with colorectal cancer

There appears to be evidence linking between obesity and cancer as well as obesity and low vitamin D, according to a paper published in BMC Cancer. However, the study authors report that the significance of vitamin D in the biological pathways associating obesity and cancer is low and they call for additional research to include all three components while dealing with bias related to dietary supplements and vitamin D receptor polymorphisms.

The international team of researchers from King’s College London and Guy’s & St Thomas’ NHS Foundation Trust, London, UK, the University of Zurich, Zurich, Switzerland, the Regional Cancer Centre Uppsala/Orebro and Uppsala University, Uppsala, Sweden, write that an estimated 20% of all cancer cases are caused by obesity and that vitamin D is believed to be one of the mechanisms underlying this association. Their paper, via a literature search, sought to summarise the evidence of these associations.

Following a literature search, they identified 32 meta-analyses on obesity and cancer with all seven meta-analyses on colorectal cancer showing a positive association between BMI and colorectal cancer risk. In addition, an addition literature search reveal a pooled relative risk of 1.52 (95% CI: 1.33-1.73) for the association between obesity and low vitamin D status. With regards to the association between circulating vitamin D levels and cancer risk, they that circulating vitamin D levels were inversely associated with cancer risk.

“The majority of meta-analyses included in our review reported positive associations 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,” they write. “…There is consistent accumulating evidence for an association between obesity and risk of certain cancer with several suggested molecular mechanisms that can potentially explain these raised risks. However, the role of vitamin D is not addressed in detail in these studies.”

In summary, they report that:

  • There was a consistent positive association between obesity and cancer with relative risks varying between 1.10 and 1.90 when addressing the existing literature
  • Their meta-analysis illustrated an association as strong as 1.50 between obesity and low vitamin D levels
  • The literature for vitamin D status and cancer risk only showed consistent evidence for an inverse association with colorectal cancer

“From these reviews, it seems that the significance of the mediating role of vitamin D in the biological pathways linking obesity and cancer is low,” they conclude. “This review emphasises that further research specifically addressing the relationship between obesity, vitamin D and cancer risk in one study is needed.”

To access this article please click here

Want more stories like this? Subscribe to Bariatric News!

Bariatric News
Keep up to date! Get the latest news in your inbox.