Bioavailability of Vitamin D in Cod Liver Oil and Multivitamin Tablets in Healthy Subjects in Norway

The main aim of the present study is to compare the bioavailability of vitamin D from cod liver oil and multivitamin tablets given to healthy individuals under the same conditions, as well as to study the influence of gender and ethnicity on vitamin D absorption. Healthy subjects will be randomised into two parallel groups receiving 10 micrograms (400 IU) per day of vitamin D3 from one fish oil capsule or one solid multivitamin tablet, respectively. Serum samples will be drawn at baseline and after four weeks (28 days) for the analysis of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, and tartrate resistant acid phosphatase in serum.