A recent study conducted by researchers at the Francis Crick Institute has found that vitamin D may play a significant role in enhancing immunity to cancer by influencing the growth of specific gut bacteria. The research, conducted on mice, showed that those with a diet rich in vitamin D exhibited not only better resistance to cancer but also improved responses to immunotherapy treatment.

The study focused on the relationship between vitamin D and the gut microbiome, particularly how it facilitates the growth of the beneficial bacteria Bacteroides fragilis. Mice with higher levels of this bacteria demonstrated enhanced immunity to cancer. Furthermore, administering the bacteria alone to mice resulted in improved tumor resistance, especially when combined with sufficient levels of vitamin D.

This discovery aligns with previous data from Denmark involving 1.5 million people, which suggested a correlation between higher vitamin D levels and a reduced cancer risk, as well as a better response to immune-based cancer therapies.

Published in the Science journal, the study was supported by several institutions, including Cancer Research UK, the UK Medical Research Council, and the Wellcome Trust. While the findings are preliminary and primarily in mice, they suggest a potential new avenue for cancer treatment in humans that warrants further investigation.