Vitamin D drastically reduces cancer risk

Emobileclinic Researchers’ corner

Emobileclinic Reporter: Femi Fayomi

In a recent publication in the Journal PLOS One, vitamin D has been found to be an important tool for the prevention of cancer according to the findings of researchers from the University of California-San Diego (UCSD) School of Medicine. This submission came after they analyzed the link between vitamin D and cancer to determine what blood level of vitamin D was required to effectively reduce cancer risk.

One of the authors, Cedric Garland, adjunct professor in the UCSD School of Medicine Department of Family Medicine and Public Health, says their study is the first to put numbers on this relationship, as he explains: “We have quantitated the ability of adequate amounts of vitamin D to prevent all types of invasive cancer combined, which had been terra incognita until publication of this paper.” Vitamin D, which is produced by the body through exposure to sunshine, helps the body control calcium and phosphate levels. The first study that linked low vitamin D with cancer was published in 1980s by Prof. Garland and his late brother Frank. They found people who lived at higher latitudes and thus had less access to sunlight had lower levels of vitamin D and were more likely to develop bowel cancer.

The only accurate way to measure vitamin D in the body is to measure the level of 25-hydroxyvitamin D in the blood. The kidneys convert 25-hydroxyvitamin D into the active form that helps control calcium and phosphate levels.Scholars have not been able to state categorically what the level of vitamin D should be in the body before it could help prevent cancer. However, the Institute of Medicine (IOM) in the year 2010 recommended a target of 20 ng/ml for bone health, which could be met in most healthy adults (aged 19-70), with the equivalent of 600 IU of vitamin D each day. Since then, other groups have argued that the target level should be higher, at 50 ng/ml or more.

In the new study, Prof. Garland and colleagues wanted to find out what blood level of vitamin D effectively reduces cancer risk. They took an approach that is not normally used. Results from two previous types of study were used: one a clinical trial of 1,169 women and the other a prospective study of 1,135 women. For some of their analysis, they kept the two data sets separate and compared them, and in another part, they pooled the data to create a larger sample. Vitamin D level of 40 ng/ml or higher tied to 67% lower cancer risk The median blood level of 25-hydroxyvitamin D in the participants in the clinical trial was 30 ng/ml, and in the participants in the prospective study, it was 48 ng/ml. The researchers found that the rate of cancer incidence in the clinical study group (that had the lower median vitamin D level) was higher than in the prospective study group. The figures were 1,020 cases per 100,000 person-years and 722 per 100,000 person-years, respectively.

Furthermore, it was found that the cancer rates went down as 25-hydroxyvitamin D levels rose; women whose vitamin D level was 40 ng/ml or higher had a 67% lower risk of developing cancer than women whose vitamin D level was 20 ng/ml or lower. The researchers did not say what the optimum intake level of vitamin D should be – or how it should be generated, whether by greater exposure to sunlight, dietary changes or supplements.

Prof. Garland says their findings simply show that it is possible to see reduced cancer risk when blood levels of vitamin D reach 40 ng/ml, and that higher than this, the risk drops even further. He and his colleagues conclude: “Primary prevention of cancer, rather than expanding early detection or improving treatment, will be essential to reversing the current upward trend of cancer incidence worldwide. This analysis suggests that improving vitamin D status is a key prevention tool.” The researchers add that “Primary prevention of cancer, rather than expanding early detection or improving treatment, will be essential to reversing the current upward trend of cancer incidence worldwide. This analysis suggests that improving vitamin D status is a key prevention tool.