Cancer mortality rates vary inversely with geographic latitude and solar ultraviolet-B doses. This relationship may be due to an inhibitory role of vitamin D on cancer development. The relationship between vitamin D and cancer appears to be stronger for studies of cancer mortality than incidence. Because cancer mortality reflects both cancer incidence and survival, the difference may be due to ...

Exposure to solar ultraviolet B radiation during the summer months is the main source of vitamin D (VD) for people living in northern latitudes. The aim of this study was to determine whether artificial narrowband ultraviolet B (NB-UVB) whole-body exposures could maintain VD levels in winter. The intervention group received 2 standard erythema doses (SEDs) of NB-UVB exposures every second week ...

BACKGROUND The concurrent impact of repeated low-level summer sunlight exposures on vitamin D production and cutaneous DNA damage, potentially leading to mutagenesis and skin cancer, is unknown. OBJECTIVES This is an experimental study (i) to determine the dual impact of repeated low-level sunlight exposures on vitamin D status and DNA damage/repair (via both skin and urinary biomarkers) in l...

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are...

The diffuse sky radiation component in the ultraviolet wavelengths is often at least 50% of the global irradiance under clear skies, and is the dominant component of ultraviolet global radiation under translucent overcast skies. The distribution of sky radiance was measured in a rural area and modeled for wavelength bands of ultraviolet-B (UVB, 280-320 nm) and ultraviolet-A (UVA, 320-400 nm). S...

The penetration of solar erythemal ultraviolet radiation has been measured in the shade of a gum (Eucalyptus sp.) and a she oak (Casaurina) tree, both on a horizontal plane and with polysulphone dosimeters to human anatomical sites. This has provided new data useful for protection strategies against harmful ultraviolet radiation. For larger solar zenith angles, the relative penetration of solar...

The seminal paper by Garland and Garland 1 continues the tradition of observation and inference leading the way to discovery of new methods for preventing or curing disease. Their paper broke ground by marshalling the evidence for the vitamin D-cancer hypothesis. Their work directly confronted the prevailing paradigms that the main risk factors for colon cancer were deficient fibre intake, exce...

1,25-dihydroxyvitamin D3 (VD3), an active form of Vitamin D, is photosynthesized in the skin of vertebrates in response to solar ultraviolet B radiation (UV-B). VD3 deficiency can cause health problems such as immune disease, metabolic disease, and bone disorders. It has also been demonstrated that VD3 is involved in reproductive functions. Female sex hormones such as estrogen and progesterone ...

BACKGROUND Vitamin D status influences skeletal health, the risk of falls and fractures, and muscle health, and it has been associated with inflammatory, infectious, cardiovascular and metabolic disorders in addition to some cancers. Prevailing intracellular infections such as tuberculosis are speculated to relate to vitamin D status. The vitamin D sources are dietary and dermal, the latter dep...

Apart from its classical function in bone and calcium metabolism, vitamin D is also involved in immune regulation and has been linked to various cancers, immune disorders and allergic diseases. Within the innate and adaptive immune systems, the vitamin D receptor and enzymes in monocytes, dendritic cells, epithelial cells, T lymphocytes and B lymphocytes mediate the immune modulatory actions of...