Vitamin D Binding Globulin in the Rat

Abstract

Conclusions

The vitamin D binding globulin of the rat exhibits a much greater affinity for vitamin D₃ than for vitamins D₂ and D₄. The addition of a hydroxyl group to the side chain of any of the vitamins increases their affinity for the protein. At physiologic dose levels, lipoproteins would play almost no role in the in vivo binding of vitamin D₃ in rat serum. It is suggested that the affinity of a vitamin for the vitamin D binding globulin may play an important role in the biologic effectiveness of the molecule.