Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun’s ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is amajor public health problem;more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major form...

Ultraviolet radiation (UVR) has been associated with various health outcomes, including skin cancers, vitamin D insufficiency, and multiple sclerosis. Measurement of UVR has been difficult, traditionally relying on subject recall. We investigated trends in satellite-derived UVB from 1978 to 2014 within the continental United States (US) to inform UVR exposure assessment and determine the potent...

Most humans depend on sun exposure to satisfy their requirements for vitamin D. Solar ultraviolet B photons are absorbed by 7-dehydrocholesterol in the skin, leading to its transformation to previtamin D3, which is rapidly converted to vitamin D3. Season, latitude, time of day, skin pigmentation, aging, sunscreen use, and glass all influence the cutaneous production of vitamin D3. Once formed, ...

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun’s ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is amajor public health problem;more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major form...

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun’s ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is amajor public health problem;more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major form...

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun’s ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is amajor public health problem;more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major form...

This disrupts the vital functions of the skin, which include:  Acting as a physical barrier for the body against mechanical and thermal injury, and hazardous substances  Helping to regulate the loss of moisture  Offering a degree of protection from the harmful effects of ultraviolet (UV) radiation  Providing sensory and autonomic functions, i.e. touch  Regulating body temperature  Acting ...

Deaths during the 1918-1919 influenza pandemic have been linked to both the influenza virus and secondary bacterial lung infections. Case fatality rates and percentage of influenza cases complicated by pneumonia were available from survey data for twelve United States locations in the 1918-1919 pandemic. This study analyzes case fatality rates and cases complicated by pneumonia with respect to ...

Sunlight is essential for life, moderate exposure to ultraviolet radiation contributes to the synthesis of vitamin D, but much exposure can be harmful to skin, eyes and immune system. One of the biggest problems when exposed to the sun is skin cancer. In Mexico, around 1,000 cases occur annually; the states with the highest record of cancer deaths are: Mexico City, Mexico State, Veracruz y

Low vitamin D levels have been found in patients with autoimmune diseases, including type I diabetes, rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. The main source of vitamin D is exposure to sunlight, but the same solar radiation is known to exacerbate lupus erythematosus. We investigated the prevalence of vitamin D insufficiency in patients with cutaneous lupus er...