|  | Diet Nutrition | Vitamins

Is Sunshine Beneficial Through a Window Glass?

Sunlight filtered through windows is not healthy for humans. In fact, it can actually be harmful and increase the risk for skin cancer from UV-A exposure. UV-B radiation is the beneficial form, and common window glass filters these rays.

  1. UV-A Radiation

    • Sunlight creates two types of ultraviolet radiation -- A and B. UV-A is the "tanning" rays and responsible for darkening the skin.

    UV-B Radiation

    • UV-B rays are superficially damaging, and they are more likely to cause sunburns. However, UV-B radiation is critically important to humans. It stimulates the production of vitamin D and melanocytes that produce melanin to protect the skin from UV-A.

    UV-B and Windows

    • Most UV-B rays cannot penetrate windows, and thus you do not receive their healthful benefits from light filtered through a windowpane. Experts recommend taking a vitamin D supplement if you are not getting enough sunlight, particularly in the winter.

    Skin Cancer Risk

    • Ordinary windows do not filter UV-A rays, and they are the most harmful in terms of causing skin cancer. This type of radiation penetrates the skin more deeply. Prolonged exposure to UV-A will also cause premature aging of the skin.

    UV-A Filtered Windows

    • Because of rising skin cancer rates, it is becoming more common for all types of windows to be made with either with UV-A filtering film or low-emittance coating, another type of UV filter.

Vitamins - Related Articles