It is an object of the present invention to provide methods for producing vitamin D that gives improved yields and reduced side product contamination. In various aspects, these methods provide for production of vitamin-D.sub.2 using ergosterol as provitamin D.sub.2 or a dihydroxy derivative thereof as a starting material, or production of vitamin-D.sub.3 using 7-dehydrocholesterol as provitamin D.sub.3 or a dihydroxy derivative thereof as the starting material. The methods described herein comprise irradiating the starting material in a solution including an organic or inorganic base with light in the wavelength range 245-360 nanometers (nm) to obtain a product containing pre-vitamin-D.sub.2 or pre-vitamin-D.sub.3, and heating the product to convert the resulting pre-vitamin-D.sub.2 or pre-vitamin-D.sub.3 to vitamin D.sub.2 or vitamin D.sub.3. In various embodiments, these methods further comprise recovering vitamin D.sub.2 or vitamin D.sub.3 from this reaction as a purified product.

According to the present invention, there can be provided a process for producing 7-dehydrocholesterol (7DHC), comprising culturing, in a medium, a 7DHC-producing Labyrinthulea microorganism in which sterol 24-C-methyltransferase activity is reduced or lost as compared to a parent strain, allowing 7DHC to be produced and accumulated in the culture, and collecting the 7DHC from the culture; and a process for producing vitamin D3, comprising irradiating, with ultraviolet light, 7-dehydrocholesterol produced by the production process.

According to the present invention, there can be provided a process for producing 7-dehydrocholesterol (7DHC), comprising culturing, in a medium, a 7DHC-producing Labyrinthulea microorganism in which sterol 24-C-methyltransferase activity is reduced or lost as compared to a parent strain, allowing 7DHC to be produced and accumulated in the culture, and collecting the 7DHC from the culture; and a process for producing vitamin D3, comprising irradiating, with ultraviolet light, 7-dehydrocholesterol produced by the production process.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

A reagent composition for releasing vitamin D compounds bound to vitamin D-binding protein and an in vitro method for the detection of a vitamin D compound in which the vitamin D compound is released from vitamin D-binding protein by the use of this reagent composition as well as the reagent mixture obtained in this manner. Also disclosed is the use of the reagent compositions to release vitamin D compounds as well as a kit for detecting a vitamin D compound.

According to the present invention, there can be provided A process for producing 7-dehydrocholesterol (hereinafter, 7DHC), comprising culturing, in a medium, a 7DHC-producing Labyrinthulea microorganism in which the 7DHC reducing activity is reduced or lost as compared to a parent strain through deletion, substitution, or addition of at least one base in a gene which is present in the chromosomal DNA of the parent strain and encodes a protein having 7DHC reducing activity, and the microorganism produces 7DHC, allowing 7DHC to be produced and accumulated in the culture, and collecting the 7DHC from the culture; and a process for producing vitamin D3, comprising irradiating, with ultraviolet light, the 7DHC produced by the production process.

According to the present invention, there can be provided A process for producing 7-dehydrocholesterol (hereinafter, 7DHC), comprising culturing, in a medium, a 7DHC-producing Labyrinthulea microorganism in which the 7DHC reducing activity is reduced or lost as compared to a parent strain through deletion, substitution, or addition of at least one base in a gene which is present in the chromosomal DNA of the parent strain and encodes a protein having 7DHC reducing activity, and the microorganism produces 7DHC, allowing 7DHC to be produced and accumulated in the culture, and collecting the 7DHC from the culture; and a process for producing vitamin D3, comprising irradiating, with ultraviolet light, the 7DHC produced by the production process.

The present invention relates to new vitamin D compounds which are bonded to a labelling group at the C3 stereocentre by means of a linker. The present invention further relates to a method for producing these vitamin D compounds and to the use of an intermediate for producing these compounds. The present invention also relates to a method for quantitatively determining vitamin D using a vitamin D compound according to the invention as a tracer. Furthermore, the present invention relates to a reagent for determining vitamin D, containing a compound according to the invention, and to the use thereof for determining vitamin D.

The present invention relates to new vitamin D compounds which are bonded to a labelling group at the C3 stereocentre by means of a linker. The present invention further relates to a method for producing these vitamin D compounds and to the use of an intermediate for producing these compounds. The present invention also relates to a method for quantitatively determining vitamin D using a vitamin D compound according to the invention as a tracer. Furthermore, the present invention relates to a reagent for determining vitamin D, containing a compound according to the invention, and to the use thereof for determining vitamin D.

The present invention provides methods, devices, and compositions to rapidly detect analytes, including small analytes, using a lateral flow device. Described herein is such a lateral flow device that can detect and quantify vitamin D in a whole blood, serum, or plasma sample by employing a sandwich-based immunoassay.