Search Results for: Rhododendrons not grafted
radiograph of a child with rickets , usually caused by insufficient vitamin d main article: vitamin d uvb radiation with a wavelength of – nanometers penetrates uncovered skin and converts cutaneous -dehydrocholesterol to previtamin d , which in turn becomes vitamin d . [ ] [ ] [ ] uvb radiation does not
penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin d. [ ] time of day, time of year, geographic latitude, ground altitude, cloud cover, smog, skin melanin content, and sunscreen are among the factors that greatly affect uv intensity and vitamin d synthesis, [...
https://en.wikipedia.org/wiki/Health_effects_of_sunlight_exposure