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Half-life of vitamin D varies

Note: The following are my best estimates based on lots of publications

Please inform me via email of corrections and additions.
Thanks, Henry Lahore  August 16, 2012    Email Henry Lahore

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Vitamin D Half-Life is '1-6 weeks''

Half-life: the time till half of the quantity still exists
Example: Start with 30 ng of vitamin D and half-life of 6 weeks, then 15 ng at 6 weeks

Half-life varies with:

  • Vitamin D level
  • Vitamin D Source: guesses for 20 ng (shorter half-life for >50 ng)
    6 weeks: Sun/UV
    3 weeks: D3 supplements
    1 week: D2 supplements
  • 1-2 day: Trauma/surgery

Half-life might also vary with such things as:

  • Sickness - especially inflammation 2 days?
  • Amount of Calcium in bloodstream
  • Race
  • Obesity
  • Type of food
  • Ratio of UVB to UVA

Wikipedia - Biological half-life

Clinical practice: 4 to 5 X the half-life to reach steady state
   Example: 4X 2-6 week ==> 2-6 month to reach steady state

It appears that

@ 10 nanograms: half-life (sun) = about 12 weeks
@ 50 nanograms: half-life (sun) = about 2 week

Fuzzy graph of vitamin D half-life vs source

see wikipage http://www.vitamindwiki.com/tiki-index.php?page_id=3133

See also VitaminDWiki

see wikipage: http://www.vitamindwiki.com/tiki-index.php?page_id=2475

Notion of Vitamin D benefit vs dosing frequency for > 50 nanograms
see wikipage http://www.vitamindwiki.com/tiki-index.php?page_id=2475

Example at 27 nanograms, half-life is about 7 weeks
see wikipage http://www.vitamindwiki.com/tiki-index.php?page_id=1046

Example of half life while adding 10,000 IU of vitamin D3
Nutrition: US recommendations fail to correct vitamin D deficiency
http://www.nature.com/nrendo/journal/v5/n10/fig_tab/nrendo.2009.178_F1.html
From Heaney 2003

Example of half life vitamin D2
Image

Example of vitamin D from the sun 1 week to double
Image
same reference has an adjustment function to account for the photodegradation of vitamin D by the sun
Image

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See also VitaminDWiki - UVB with/without UVA


short url = http://is.gd/halflifeD


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Health Problems and D

{#s as of April 10, 2014}