The Health Benefits of Solar Irradiance and Vitamin D and the Consequences of Their Deprivation

Originally recognized for reducing the risk of rickets, the benefits of vitamin D were extended in the past three decades, to protection against many non-calcemic diseases. The primary source of vitamin D is production by solar ultraviolet B (UVB) irradiance. In this paper, evidence is reviewed that vitamin D reduces the risk of about 17 types of cancer; bacterial infections for diseases such as dental caries, periodontitis, septicemia, and tuberculosis; viral infections such as respiratory infections and EpsteinBarr virus; autoimmune diseases such as asthma and multiple sclerosis; cardiovascular diseases such as coronary heart disease, diabetes, and stroke; and dementia. Several studies have also reported longer life expectancy with higher vitamin D supplement or serum 25-hydroxyvitamin D levels.