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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Is it true that it takes 48 hours after being exposed to the sun for vitamin D to be absorbed by the blood? Is it also true that if you wash your body with soap vitamin d is dissolved and, thererofe, not absorbed by the body? If yes, how can one not wash for 48 hours, especially in the summer? Thank you!

Ask the Vitamin D Council

Asked by  kmantadaki31746000 on July 18, 2016


  • kmantadaki31746000
     kmantadaki31746000 on

    See title

    Answered by  kmantadaki31746000 on

  • IAW
     IAW on

    Brant said:
    Skin first produces previtamin D3 in plasma membranes of skin cells, and about 50% of this previtamin D3 is converted to vitamin D3 within 2 hours.
    Holick M. “Photobiology of Vitamin D” Vitamin D: Second Edition, Chapter 3. 2005.
    (The) Body begins converting vitamin D3 from the skin to 25(OH)D at 10 hours, with 25(OH)D levels peaking at 24 hours.
    Dr. Cannell said “Humans make some vitamin D on the surface of their skin, which water washes off”. “How much humans make on the surface and how much inside the skin, no one knows.”
    So really “some” but not all is on the surface. No one has yet to answer the why or what for. So “no” you are not washing it “all” away.

    Answered by  IAW on