A study conducted on Japanese adults on Thursday, found that higher levels of Vitamin D in the blood may be linked to a lower risk of developing certain cancers. “These findings support the hypothesis that Vitamin D has protective effects against cancers at many sites,” researchers reported in a study published in The BMJ medical journal. Vitamin D is made by the skin in response to sunlight. By maintaining calcium levels in the body, it helps keep bones, teeth, and muscles healthy. Researchers made the first connection between vitamin D deficiency and some cancers in 1980 when they noted populations at higher latitudes (with less available sunlight) were more likely to be deficient in Vitamin D, which is produced by the body through exposure to sunshine, and experience higher rates of colon cancer. Subsequent studies found vitamin D links to other cancers, such as breast, lung, and bladder. Studies to date, however, have been carried out mainly in European and North American people. As natural Vitamin D concentrations can vary by ethnicity, researchers from half-a-dozen Japanese medical schools and institutes set out to determine the potential for lowering cancer risk in Asians. They analyzed the public health records of 33,736 men and women aged 40 to 69. At the start of the study, participants provided detailed information on their medical history, diet, and lifestyle. Blood samples were taken to measure Vitamin D levels. The researchers did not specify whether the trial participants used vitamin supplements or not. Taking into account seasonal variations, the group was divided into four groups, ranging from the lowest to highest concentration of Vitamin D. Participants were then monitored for 16 years on average, during which time 3,301 new cases of cancer were recorded. After adjusting for well-known cancer risk factors – age, weight, smoking, and alcohol intake, for example – the researchers found that, overall, higher Vitamin D levels were associated with a 20 percent lower cancer risk for both genders.