BACKGROUND Neither the efficiency of the 25-hydroxylation of vitamin D nor the steady state relation between vitamin D(3) and 25-hydroxyvitamin D [25(OH)D] has been studied in humans. OBJECTIVE We aimed to examine the relation between serum vitamin D(3) and 25(OH)D in normal subjects after either oral administration of vitamin D(3) or ultraviolet-B radiation across a broad range of inputs. ...

The ultraviolet (UV)-B spectrum in solar UV radiation is essential for stimulating the epidermal production of vitamin D but also damages DNA and causes cancer in exposed cells. We examined the role of solar UV in inducing DNA damage in blood lymphocytes and the possible modulation of this damage by serum 25-hydroxy vitamin D (25(OH)D) in 207 male and female participants from South Australia. P...

Sun exposure has been associated with lower death rates for pancreatic cancer in ecological studies. Skin exposure to solar ultraviolet B radiation induces cutaneous production of precursors to 25-hydroxy (OH) vitamin D (D) and is considered the primary contributor to vitamin D status in most populations. Pancreatic islet and duct cells express 25-(OH) D(3)-1alpha-hydroxylase that generates the...

Studies of the UV-radiation are the most actual ecological problems that are called by ozone depletion increasing the level of biologically active solar UV-B radiation in the biosphere. The air pollution and atmospheric aerosols prevent penetrating appropriate dose UV radiation, which is beneficial for people, specifically due to production of vitamin D3 in skin from its precursor 7dehydrochole...

There is compelling epidemiological evidence that the risk of developing multiple sclerosis is increased in association with low levels of sun exposure, possibly because this is associated with low vitamin D status. Recent work highlights both vitamin D and non-vitamin D effects on cellular immunity that suggests that higher levels of sun exposure and/or vitamin D status are beneficial for both...

This paper reviews briefly the evidence for an association between various measures of UV radiation (UVR) exposure and the development of cancer. Issues such as data quality, study design, measurement variation, comparability of studies, and quantification of UV exposure in relation to skin cancer are discussed. A range of exposure, based on skin type, might be appropriate: from 5 min a day thr...

In this review, reports were retrieved in which vitamin D status, as assessed by serum 25-hydroxyvitamin D [25(OH)D] levels, was measured in South African population groups with varied skin colours and ethnicities. Healthy children and adults were generally vitamin D-sufficient [25(OH)D level >50 nmol/L] but the majority of those aged above 65 years were deficient. A major role for exposure to ...

There is an ongoing debate how to balance between beneficial and adverse effects of UV-exposure. On the one hand, solar UV-radiation represents the most important environmental risk factor for the development of non-melanoma skin cancer. Therefore, sun protection is a key principle to prevent these malignancies, especially in risk groups. On the other hand, artificial or solar UV-radiation is r...