The relationship between vitamin D deficiency and certain cancers was first reported in 1980. They determined that people residing at higher latitudes, were more likely to have Vitamin D deficiencies also had higher rates of colon cancer. Vitamin D has since been linked to other cancers including breast, lung, and bladder.
A study published in April 6, 2016 issue of PLOS One, conducted at University of California, San Diego School of Medicine, found that higher levels of vitamin D, specifically serum 25-hydroxyvitamin D, are associated with a decreased risk of cancer.
In this new study, the team sought to pinpoint the blood level of vitamin D (specifically 25-hydroxyvitamin D) needed to effectively reduce the risk of cancer.
They found that the age-adjusted incidence of cancer declined with higher 25(OH)D levels specifically women with 25(OH)D concentrations of 40 ng/ml or more had a 67 percent lower risk of cancer than the women with levels of 20 ng/ml or less.
The authors of the study suggested that more resources should be spent preventing cancer rather then treating it and vitamin D could be an effective tool.
From the Abstract
They study took two cohorts of women aged 55 years and older across a broad range of 25(OH)D concentrations. Cancer incidence over a multi-year period (median: 3.9 years) was compared according to 25(OH)D concentration. Kaplan-Meier plots were developed and the association between 25(OH)D and cancer risk was examined with multivariate Cox regression using multiple 25(OH)D measurements and spline functions. The study included all invasive cancers excluding skin cancer.
Results Age-adjusted cancer incidence across the combined cohort (N = 2,304) was 840 cases per 100,000 person-years (1,020 per 100,000 person-years in the Lappe cohort and 722 per 100,000 person-years in the GrassrootsHealth cohort). Incidence was lower at higher concentrations of 25(OH)D. Women with 25(OH)D concentrations ≥40 ng/ml had a 67% lower risk of cancer than women with concentrations <20 ng/ml (HR = 0.33, 95% CI = 0.12–0.90).
Conclusions 25(OH)D concentrations ≥40 ng/ml were associated with substantial reduction in risk of all invasive cancers combined.