- Vitamin D would prevent severe forms of cancer.
- On the other hand, it works best in people who have a normal body mass index, i.e. between 18 and 25.
Vitamin D is loaded with benefits. Researchers at Harvard University’s Brigham Women’s Hospital (USA) have shown that taking vitamin D was associated with a 17% overall reduction in cancer risk. This reduction could go up to 38% for people who have a normal body mass index. The article was published on November 18, 2020 in Jama Network Open.
Vitamin D and Omega-3 for five years
To arrive at this conclusion, the research team looked at the VITAL trial (Vitamin D and Omega-3 Trial) which ended in 2018. It showed that vitamin D did not reduce the incidence cancer but reduced the risk of death. With this new study from VITAL, researchers want to know if vitamin D supplementation was linked to the risk of metastatic or fatal cancer.
The VITAL study took place over five years and focused on 25,000 women and men aged 50 or over who did not have cancer. Throughout the experiment, the participants were divided into four groups: those entitled to vitamin D (2,000 international units per day) and omega-3s; those with vitamin D and a placebo; those with omega-3s and a placebo; those with two placebos.
The main criteria sought by the team focused on the incidence of cancer and the major cardiovascular elements that would have seen their situation change. In a second step, the team examined the effects of body mass index (BMI) on cancers as well as to see if a possible correlation between the reduction in cancer cases and vitamin D supplementation or not.
Of the 25,000 participants, 1,617 were diagnosed with invasive cancer (breast, prostate, colorectal, lung or others) during the five years of the test. Of the 13,000 participants who received vitamin D, 226 were diagnosed with advanced cancer versus 274 among those who received a placebo. Likewise, of the 7,843 participants who had a normal BMI (between 18 and 25) and who were receiving vitamin D, only 58 of them were diagnosed with cancer, compared to 96 people taking a placebo.
“These results suggest that vitamin D may reduce the risk of developing advanced cancers, says Paulette Chandler, epidemiologist in preventive medicine at Brigham Women’s Hospital. Vitamin D is a supplement that is readily available, inexpensive, and has been used and studied for decades. Our findings, in particular the strong reduction in risk observed in people of normal weight, provide new insight into the relationship between vitamin D and cancer progression..”
Vitamin D and its many benefits
Although at first glance the results seem to be due to chance, there is however previous evidence that body mass can affect the action of vitamin D. Indeed, obesity and the inflammation that overweight creates decreases. the effectiveness of vitamin D. Likewise, randomized trials of vitamin D have shown that it is more beneficial in people with a normal body mass index.
Vitamin D deficiency is common in cancer patients. A previous study showing deficiency rates of 72% in cancer patients. People with high levels of body fat are also at increased risk of having multiple cancers.
“Our findings, along with those of previous studies, support the ongoing evaluation of vitamin D supplementation for the prevention of metastatic cancers – a biologically plausible link, confirms Paulette Chandler. Further studies in cancer patients investigating the role of BMI are warranted.”