There is ample and compelling evidence that a blood level of 30-50 ng/mL is necessary for optimal health. In the absence of adequate sun exposure, 1,000 IU vitamin D daily for children and adults is required to achieve these levels.
With the recent announcement that health care expenditures in the United States reached $1.7 trillion in 2003, accounting for 15.3 percent of the
U.S. gross domestic product,201 more effort must be made to maintain optimal health and prevent disease.
It is becoming increasingly apparent that vitamin D sufﬁciency is required for optimal health; however, most people living outside the tropical regions do not have serum 25(OH)D levels high enough for optimal health. Vitamin D is beneﬁcial at all stages of life. It is hoped that researchers will increase their focus on the importance of vitamin D for optimal health and reduced risk of many diseases, that public health guidelines will be revised to acknowledge solar UVB irradiation is more beneﬁcial than harmful, and that people should try to maintain optimal serum levels of 25(OH)D through a combination of diet, supplements, and solar and artiﬁcial UVB irradiation.
Several recent reports have found vitamin D is beneﬁcial, not only for cancer prevention, but also for those recently diagnosed with cancer. The ﬁrst two such reports were from Norway, where it was observed those whose breast, colon, or prostate cancer is discovered in summer or fall have a higher survival rate than those for whom the discovery is made in winter or spring.202,203 It was hypothesized that these
observations were related to vitamin D status at the time of discovery, with a higher 25(OH)D level providing an improved prognosis. In a vitamin D supplementation study, for those with elevated prostate-spe-ciﬁc antigen (PSA) levels, a dose of 2,000 IU/day led to an increase of 75 percent in the average PSA doubling time; in other words, PSA levels increased more slowly.204 This appears to be in contrast to data above that indicated vitamin D in high doses might contribute to prostate cancer. There may be a difference in effect of vitamin D at different stages of prostate cancer development – a subject of ongoing research.
In a poster presented at a recent conference, it was reported that male health professionals with early stage non-small cell lung cancer with higher vitamin D indices (based on geographic location, race, leisure time outdoor activities, oral vitamin D, and body mass index) had a higher survival rate than those with lower vitamin D indices.205 These results strongly suggest that those diagnosed with cancer should be immediately placed on a vitamin D enhancement program, especially African Americans, who have a heretofore unexplained lower cancer survival rate than white Americans206 and have a much lower vitamin D status than white Americans.156
Michael F. Holick received funding from the UV Foundation and the National Institutes of Health through grants #M01RR00533 and #AR3696312.