Taking vitamin D supplements could reduce risk of advanced cancer by 17pc, study suggests

Taking vitamin D supplements could reduce the overall risk of advanced cancer by 17 per cent, a study has suggested.

The risk reduction could be as high as 38 per cent among those who have a healthy weight and are consuming vitamin D.

The results, published in the journal Jama Network Open, are based on the Vitamin D and Omega-3 Trial (Vital), which concluded in 2018.

Back then, scientists found that vitamin D did not reduce overall incidence of cancer but there was a decreased risk of cancer deaths.

But a secondary analysis led by Brigham And Women's Hospital in Boston, Massachusetts, US, suggests vitamin D is associated with a 17 per cent risk reduction for advanced cancer overall, and a 38 per cent reduction among those with normal body mass index (BMI).

Dr Paulette Chandler, a primary care physician and epidemiologist in the Brigham And Women's Hospital, and one of the authors on the study, said: "Our findings, especially the strong risk reduction seen in individuals with normal weight, provide new information about the relationship between vitamin D and advanced cancer."

More than 25,000 people took part in the Vital study, which spanned more than five years.

The participants included men aged 50 or above and women 55 or older who did not have cancer when the trial began.

The test subjects were divided into four groups; the first group took a daily dose of vitamin D along with omega-3s, the second group took vitamin D plus a placebo, the third consumed omega-3s plus placebo, and the fourth group only had placebos.

In their secondary analysis, researchers evaluated the risk of developing advanced cancer among participants who did or did not take vitamin D supplements during the trial.

They also examined whether an individual's BMI played a role.

Among the participants, 1,617 were diagnosed with an invasive form of cancer - such as breast, prostate, colorectal, lung - over the next five years.

Among those who received vitamin D, 226 were diagnosed with advanced cancer, compared to 274 who received the placebo.

Of those with a normal BMI (less than 25) taking vitamin D, 58 people were diagnosed with advanced cancer compared with 96 taking the placebo.

The researchers believe obesity and associated inflammation may decrease the effectiveness of vitamin D.