Background: Solar ultraviolet-B (UVB) and vitamin D have been found inversely correlated with cancer incidence, mortality, and survival rates in many studies.
Materials and methods: In this work, two sets of cancer data were used: age-adjusted cancer incidence and mortality rates in 2002 for 21 Western developed countries and cancer survival data from Eurocare-3 for nine European countries for cancer diagnosed from 1990 to 1994. The data were used in ecologic studies with respect to latitude, an index of solar UVB irradiance, and dietary supply factors for 1985.
Results: Statistically significant correlations of effective or actual survival rates with increasing latitude were found for breast, colon, gastric, lung, ovarian, pancreatic, prostate and renal cancer, and non-Hodgkin's lymphoma. Five-year survival rates south of 50 degrees N were 20%-50% higher than those near 55 degrees N.
Conclusion: These results provide additional support for an increase in cancer survival rates linked with natural vitamin D.