Vitamin D may play an important role in cancer prognosis

http://www.eurekalert.org/pub_releases/2014-06/bmj-vdm061314.php

PUBLIC RELEASE DATE: 17-Jun-2014
Contact: Stephanie Burns
BMJ-British Medical Journal
Vitamin D may play an important role in cancer prognosis

Low vitamin D linked to high risk of death from all causes including cancer and cardiovascular disease

The main source of vitamin D is its production in skin thanks to the sun. Women are more prone to low vitamin D than men - and due to differing weather conditions, concentrations vary in populations across the world.

Vitamin D deficiency is especially common among the elderly who often have less sun exposure, but it is unclear what effect the production of vitamin D has on death.

So researchers investigated the association of vitamin D with deaths from all-causes, cardiovascular diseases and cancer. They paid particular attention to differences between countries, sexes and age groups.

Data were taken from seven population-based cohorts from the US and across Europe. All study participants were aged 50-79.

Results show that there was no clear trend of vitamin D by age, but average levels were consistently lower among women than men. Average levels increased with education, were lowest in obese individuals and higher among subjects who exercised.

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During 16 years of follow-up, there were 6,695 deaths in 26,018 patients - 2,624 from cardiovascular diseases and 2,227 from cancer.

An association was found between those with the lowest levels of vitamin D and death from cardiovascular disease - in people with and without a history of the disease- and deaths from cancer in those with a history of the disease. No association was found between low vitamin D levels and deaths from cancer in those without a history of the disease.

The researchers say this shows an important role of vitamin D in the prognosis of cancer, although they add "we cannot exclude reverse causality, that is, that the cancer might have led to low vitamin D levels." There was also a dose-response relationship which was unchanged after excluding patients with a history of cardiovascular disease and cancer.

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