Danielle Moore
Taking vitamin D may not necessarily mean you have a lower risk of cancer, according to Boston researchers. But thanks to vitamin D, the risk of cancer becoming malignant and metastasizing is clearly reduced. So if you take vitamin D and get cancer, you are less likely to experience a severe course.
Rare cancer with a good supply of vitamin D
The connection between vitamin D and cancer has been researched for many years. Epidemiological studies have shown, for example, that people who live close to the equator are less likely to develop certain types of cancer and are also less likely to die from cancer. The cause was suspected to be the higher solar radiation at the equator and therefore also a better supply of vitamin D (vitamin D is formed in the skin under the influence of UV radiation).
Vitamin D reduces the risk of dying from cancer
Laboratory studies with cancer cells or mice had also shown that vitamin D could slow down cancer growth. However, randomized clinical trials with humans did not bring any clear results. While it was found that people with higher levels of vitamin D had a lower risk of developing cancer (such as those associated with breast cancer), a 2019 study showed that cancer patients lived longer when given long-term vitamin D, however, it was unclear whether taking vitamin D could influence the risk of cancer.
The placebo-controlled vitamin D and omega-3 study (VITAL), which was completed in 2018, even showed that taking vitamin D could not reduce the risk of developing cancer. At least there was evidence in this study that vitamin D reduced the risk of dying from cancer. However, the doses used in this and many other vitamin D studies are always low and are not determined in relation to the individual actual value, which of course automatically leads to less good results.
Vitamin D reduces the risk of severe cancer by up to 38 percent
Researchers from Boston’s Brigham and Women’s Hospital have now conducted a further analysis of the VITAL study. They focused on the link between taking a vitamin D supplement and the risk of developing metastatic or fatal cancer.
The VITAL study was conducted over more than 5 years to examine the effect of dietary supplements with vitamin D and omega-3 fatty acids. Participants were men (over 50 years) and women (over 55 years) who had no cancer diagnosis at the start of the study and who had e.g. taken 2000 IU of vitamin D daily.
In the JAMA Network Open, study author, physician, and epidemiologist Dr. Paulette Chandler, summarizes the results, e.g. that vitamin D reduced the risk of developing advanced cancer by as much as 17 percent. If you checked this number only in people of normal weight (since being overweight increases the risk of cancer dramatically), it rose to 38 percent.
Being overweight inhibits the positive effects of vitamin D
In overweight people, vitamin D does not seem to be able to reduce the risk of cancer as well as in people of normal weight. It is assumed that it is the chronic inflammatory processes in overweight people that contribute to the limited effect of vitamin D.
Cancer patients often suffer from vitamin D deficiency
Since cancer patients also very often have a vitamin D deficiency (a study showed a corresponding deficiency in 72 percent of the examined cancer patients), the optimization of the vitamin D supply seems to be an important factor in the therapy, especially in cancer, to prevent a severe course of the disease (metastasis).
