BACKGROUND Recent research has suggested a relationship between vitamin D deficiency and risk of leukemia. PURPOSE Using data from the UN cancer database, GLOBOCAN, this study will determine whether a relationship exists for latitude and ultraviolet B (UVB) irradiance with incidence rates of leukemia in 175 countries. METHODS Multiple regression was used to analyze the independent associati...

Multiple sclerosis (MS) incidence and serum 25-hydroxyvitamin D (25OHD) levels vary by race/ethnicity. We examined the consistency of beneficial effects of 25OHD and/or sun exposure for MS risk across multiple racial/ethnic groups. We recruited incident MS cases and controls (blacks 116 cases/131 controls; Hispanics 183/197; whites 247/267) from the membership of Kaiser Permanente Southern Cali...

The sun is the most important source of visible and ultraviolet (UV) radiation. Even though the distance from the sun to the Earth is large – about 150×10 km – the fluence rate of solar radiation on Earth, the solar constant, is about 1 360 W/m 2 . Approximately 40% of this radiation is reflected back into space. The remaining 60% is the driving force of all life on Earth. A number of pigments ...

Citation: Sanwalka N. Vitamin D Deficiency in Indians – Prevalence and the Way Ahead. J Clin Nutr Diet. 2016, 1:1 Vitamin D is endogenously synthesized in human beings from photo conversion of 7-dehydrocholestrol in the skin to cholecalciferol on exposure to ultraviolet radiation of sun. In a tropical country like India, where sunlight exposure is abundant, vitamin D deficiency seems unlikely. ...

background: astronauts will be exposed to both chronic space radiation and acute high doses of energetic radiation of solar particle events in long-term deep space missions. the application of radioprotectors in space missions has basic limitations such as their very short time window as well as their acute toxicity and considerable side effects. the aim of the present study was to investigate ...

Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is common, has revived interest in this hormone. Vitamin D is produced by skin exposed to ultraviolet B radiation or obtained from dietary sources, including supplements. Persons commonly at risk for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or...

Multiple sclerosis (MS) is a chronic disease of the central nervous system, pathologically characterized by inflammation, demyelination, and axonal damage, presumably auto-immune in nature. Complex interactions between genetic susceptibility and environmental factors, such as vitamin D status and primary Epstein-Barr virus infection in adolescence or later in life, probably determine the MS ris...

Ultraviolet (UV) radiation has both beneficial and harmful effects on the human body. Its most important beneficial effect may be vitamin D production in the skin, also known as vitamin D photosynthesis. This is of particular interest for the elderly who often show vitamin D-deficiency. Intentional UV exposure has been recommended by different institutions in order to increase vitamin D levels....

In this issue, Bogh et al. report a study that begins to address the important public health question of skin surface area and UVB exposure dose, related to erythema, necessary to achieve a given level of vitamin D status. They demonstrate the importance of baseline vitamin D status in conducting such studies. A smaller substudy suggests that skin pigment is not a barrier to vitamin D photosynt...

A whole host of epidemiological studies have reported lower cancer rates and mortality in high-altitude regions. These studies are reviewed and discussed in detail. Evidence for the salutary role of vitamin D in protecting against cancer and other maladies will also be reviewed and discussed. The dependence of vitamin D production on sunlight and its enhancement with altitude will be demonstrat...