Vitamin D - Bioavailability

 When ingested orally, Vitamin D is absorbed via the Ileum of the Small Intestine with other dietary Fats with the aid of Bile.

 Topically-applied Vitamin D is claimed to be absorbed by the Skin.

 The half-life of circulating Vitamin D is 1 – 2 days.  The whole-body half-life of Vitamin D3 is approximately 62 days.

 Taking supplemental vitamin D with the largest meal of the day improves absorption and results in a 50% increase in serum levels of 25-hydroxyvitamin D.

 Vitamin D