A recent study highlighted the relationship of vitamin D and cancer. Early in the 1940’s, one researcher, Frank Appely, found that people in higher latitude areas had a greater incidence of death from cancer. As people in a higher latitude (less sunny) area made less vitamin D, he put foward the idea that vitamin D had a protective effect against cancer.

To explain this reasoning a bit better, vitamin D is made as a result of the contact of the sun’s rays on our skin. In less sunny areas, people generally produce less vitamin D. This is also true of people in lower altitude areas when compared to high altitude areas, although the critical factor is exposure to the sun. So, if you’re in a lower altitude area but it’s sunny (as it would be in a low latitude area), then you’d still be making a lot of vitamin D - unless you wore some kind of body-covering due to religious beliefs.

Unfortunately for people with darker skin, they produce less vitamin D than their fair-skinned kin, making them more likely to experience vitamin D deficiency. And this research indicates they have a 40% higher death rate from cancer compared to caucasians (they referenced the death rate in men, I don’t know if the same percentages apply to women).

They go on to say, however:

However the researchers were quick to stress that they do not prove that low vitamin D status is the cause of the cancer, and that such a conclusion could only be drawn after controlling vitamin D status for a lifetime

Some people are now seeking to increase the recommended daily allowance (RDA) of vitamin D, as it is linked to preventing not only some cancers, but also osteoporosis.

The researchers don’t know why vitamin D potentially has such a protective effect, but they believe it may be due to these reasons:

• by reducing the formation of blood vessels in tunours
• by increasing the mutual adherence of cells
• by fostering the efficiency of communication between cells through their gap junctions