A study in the British Medical Journal shows that people with very low vitamin D levels have an increased risk of all-cause mortality, including cardiovascular disease and cancer death. U.S. researchers Ben Schottker et al. conducted a study on the association between vitamin D and death from all causes, cardiovascular disease, and cancer death. A meta-analysis was conducted on data from participants aged 50-79 years from eight prospective cohort studies in the United States and Europe. Over 16 years of follow-up, 6,695 of 26,018 patients died, including 2,624 from cardiovascular disease and 2,227 from cancer. Serum vitamin D levels were found not to change significantly with age, but were consistently lower in women than in men. Mean vitamin D levels increased with educational status and were lowest in individuals who were obese and higher in subjects who exercised regularly. Compared to the general population, those with the lowest vitamin D levels had a 57% increased risk of death from all causes, a 65% increased risk of death from cardiovascular disease in those with a history of cardiovascular disease, a 41% increased risk of death from cardiovascular disease in those without a history of cardiovascular disease, a 70% increased risk of death from cancer in those with a history of cancer, and no increased risk of death from cancer in those without a history of cancer. Vitamin D is a fat-soluble vitamin. 90% of vitamin D in the body is produced by sunlight exposure to the skin, and only about 10% comes from food. During sunny seasons, the whole body receives sunlight for at least 20 minutes a day to produce enough vitamin D. In less sunny motives, adults can take vitamin D supplements to compensate for the reduced sun exposure, consuming about 1,000 IU-2,000 IU a day. Vitamin D levels are lower in women than in men, and serum vitamin D concentrations vary in populations around the world. Older adults are commonly deficient in vitamin D because they are usually less exposed to sunlight, but the correlation between vitamin D and mortality is not known. Studies have shown that populations with the lowest vitamin D levels are associated with increased mortality from all causes, cardiovascular disease mortality and cancer mortality (with a history of cancer). Researchers say low vitamin D levels can cause death from all causes and that vitamin D plays an important role in cancer prognosis.