Spectral character of sunlight modulates photosynthesis of previtamin D3 and its photoisomers in human skin.

  title={Spectral character of sunlight modulates photosynthesis of previtamin D3 and its photoisomers in human skin.},
  author={Julia A. MacLaughlin and R Rox Anderson and Michael F Holick},
  volume={216 4549},
The photosynthesis of previtamin D3 from 7-dehydrocholesterol in human skin was determined after exposure to narrow-band radiation or simulated solar radiation. The optimum wavelengths for the production of previtamin D3 were determined to be between 295 and 300 nanometers. When human skin was exposed to 295-nanometer radiation, up to 65 percent of the original 7-dehydrocholesterol content was converted to previtamin D3. In comparison, when adjacent skin was exposed to simulated solar radiation… Expand
Vitamin D Metabolism and the Clinical Aspects of Measuring Metabolites
  • S. J. Iqbal
  • Biology, Medicine
  • Annals of clinical biochemistry
  • 1994
Results show that continued exposure to sunlight results in the formation of biologically inert products and sunlight regulates the production of previtamin D and vitamin D] and limits the systemic availability of vitamin D]. Expand
Generation of previtamin D 3 from tachysterol 3 : a novel approach for producing vitamin D 3 in the winter
Solar ultraviolet-B (UVB) radiation is capable of converting 7-dehydrocholesterol (7-DHC) to previtamin D3 (preD3), which undergoes thermal isomerization to produce vitamin D3. Further ultravioletExpand
Chapter 2 – Photobiology of Vitamin D
Publisher Summary When human skin is exposed to sunlight, it is the solar ultraviolet B photons with energies between 290 and 315 nm that are responsible for causing the photolysis ofExpand
Is the action spectrum for the UV-induced production of previtamin D3 in human skin correct?
  • M. Norval, L. Björn, F. D. de Gruijl
  • Physics, Medicine
  • Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology
  • 2010
This work represents a milestone in research on vitamin D, but limitations in the original data should be recognised and the construction of an entirely new computational model to predict previtamin D levels is recommended. Expand
Vitamin D: Photobiological and Ecological Aspects
This Chapter summarises the discovery of vitamin D and reviews the chemistry and photochemistry of its precursors, transformations and metabolites, particularly its role in immunomodulation with consequences for protection against a variety of human diseases. Expand
Previtamin D conformations and the wavelength-dependent photoconversions of previtamin D
Abstract Conformational abundances calculated at different levels of theory have been used to derive spectral and photophysical properties of a previtamin D model compound. The individual conformerExpand
Skin: Site of the Synthesis of Vitamin D and a Target Tissue for the Active Form,1,25‐Dihydroxy vitamin D3
  • M. Holick
  • Chemistry, Medicine
  • Annals of the New York Academy of Sciences
  • 1988
It is now known that when human skin is exposed to sunlight the high energy ultraviolet photons penetrate into the epidermis and photolyze cytoplasmic pools of 7-dehydrocholesterol (provitamin D,) to previtamin D, (FIG. l). Expand
Solar ultraviolet B radiation and photoproduction of vitamin D3 in central and southern areas of argentina
  • M. Ladizesky, Zhiren Lu, +4 authors C. Mautalen
  • Chemistry, Medicine
  • Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
  • 1995
It is concluded that in Ushuaia there is a prolonged “vitamin D winter” during which cutaneous synthesis of vitamin D is absent, leading to lower serum values of 25(OH)D and contributing to the higher incidence of rickets. Expand
Vitamin D metabolism
It has been found that human skin irradiated with ultraviolet B also is able to produce calcitriol in substantial amounts and has photoprotective effects and can reduce UV‐induced deoxyribonucleic acid damage. Expand
Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin.
The dramatic influence of changes in solar UVB radiation on cutaneous vitamin D3 synthesis is quantified and the latitudinal increase in the length of the "vitamin D winter" during which dietary supplementation of the vitamin may be advisable is indicated. Expand


Regulation of cutaneous previtamin D3 photosynthesis in man: skin pigment is not an essential regulator.
Increases either in skin melanin concentration or in latitude necessitated increases in the exposure time to simulated solar ultraviolet radiation required to maximize the formation, but not the total content, of previtamin D3. Expand
Photosynthesis of previtamin D3 in human skin and the physiologic consequences.
These processes suggest a unique mechanism for the synthesis, storage, and slow, steady release of vitamin D3 from the skin into the circulation. Expand
Isolation and identification of previtamin D3 from the skin of rats exposed to ultraviolet irradiation.
The process of the photolytic activation of vitamin D precursor(s) in the skin has been elucidated by a detailed analysis of the products formed after ultraviolet light exposure, and Vitamin D3 arises exclusively from the thermal conversion of previtamin D3. Expand
A rapid and precise method for the determination of vitamin D3 in rat skin by high-performance liquid chromatography.
The most effective wavelength for the formation of vitamin D3 was confirmed to be 303 nm, which differs from the result obtained from the experiment in a test tube (295 nm), which was thought to be due to the filter effect of the malpighian layer in the epidermis of rat skin. Expand
The effects of light on the human body.
  • R. Wurtman
  • Physics, Medicine
  • Scientific American
  • 1975
The influences of light on human health is explored and it is suggested that exposure to artificial light may have harmful effects and health considerations should be incorporated into the design of light environments. Expand
Abstract— We present a semi‐empirical analytic formula for calculating the direct, diffuse and global solar middle‐ultraviolet radiation (280–340 nm) reaching the ground. The formula accommodatesExpand
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