The Pharmacokinetics of a Single Large Dose of Vitamin D3

Summary

When people eat a meal, some, but not all of the calcium in that meal is absorbed, that is, moved into the bloodstream. When the skin is exposed to sunlight during summer months, Vitamin D is made there and then modified into more active forms by the liver and kidneys. These more active forms of Vitamin D improve calcium absorption. Many adults living in the U.S. have little or no sun exposure and are low in Vitamin D. A single dose of 100,000 IU of Vitamin D3 has been used both as empiric treatment for Vitamin D deficiency as well as in controlled trials without risk of raising blood calcium to dangerous levels.This study is to determine the serum levels of Vitamin D and 25-hydroxyvitamin D (vitamin D after it has been modified by the liver) that can be expected when Vitamin D3 is given as a single oral dose of 100,000 IU.

Timeline

Start

2006-10

Primary completion

2007-03

Completion

2007-03

Publications

• Ilahi M, Armas LA, Heaney RP. Pharmacokinetics of a single, large dose of cholecalciferol. Am J Clin Nutr. 2008 Mar;87(3):688-91. doi: 10.1093/ajcn/87.3.688.

Drugs

Indications