Molecule structure of Calcifediol (CAS NO.19356-17-3):

IUPAC Name: (1S,3Z)-3-[(2E)-2-[(1R,3aS,7aR)-1-[(2R)-6-Hydroxy-6-methylheptan-2-yl]-7a-methyl-2,3,3a,5,6,7-hexahydro-1H-inden-4-ylidene]ethylidene]-4-methylidenecyclohexan-1-ol 
Molecular Weight: 400.63706 g/mol
Molecular Formula: C₂₇H₄₄O₂ 
Density: 1.01 g/cm³ 
Boiling Point: 529.2 °C at 760 mmHg 
Flash Point: 221.4 °C
Index of Refraction: 1.535
Molar Refractivity: 122.84 cm³
Molar Volume: 393.9 cm³
Surface Tension: 40.6 dyne/cm 
Enthalpy of Vaporization: 92.52 kJ/mol
Vapour Pressure: 2.07E-13 mmHg at 25 °C 
Storage Temp.: −20 °C
XLogP3-AA: 6.2
H-Bond Donor: 2
H-Bond Acceptor: 2
Rotatable Bond Count: 6
Exact Mass: 400.334131
MonoIsotopic Mass: 400.334131
Topological Polar Surface Area: 40.5
Heavy Atom Count: 29
Canonical SMILES: CC(CCCC(C)(C)O)C1CCC2C1(CCCC2=CC=C3CC(CCC3=C)O)C
Isomeric SMILES: C[C@H](CCCC(C)(C)O)[C@H]1CC[C@@H]\2[C@@]1(CCC/C2=C\C=C/3\C[C@H](CCC3=C)O)C
InChI: InChI=1S/C27H44O2/c1-19-10-13-23(28)18-22(19)12-11-21-9-7-17-27(5)24(14-15-25(21)27)20(2)8-6-16-26(3,4)29/h11-12,20,23-25,28-29H,1,6-10,13-18H2,2-5H3/b21-11+,22-12-/t20-,23+,24-,25+,27-/m1/s1
InChIKey: JWUBBDSIWDLEOM-DTOXIADCSA-N
EINECS: 242-990-9
Product Categories: Vitamin D3 analogs;Chiral Reagents;Intermediates & Fine Chemicals;Pharmaceuticals

In medicine, the Calcifediol (CAS NO.19356-17-3) blood test is used to determine how much vitamin D is in the body.

 Calcifediol (CAS NO.19356-17-3) is a prehormone which is produced by hydroxylation of vitamin D3 (cholecalciferol) in the liver.

Hazard Codes: T+
Risk Statements: 28 
R28:Very toxic if swallowed.
Safety Statements: 28-36/37-45 
S28:After contact with skin, wash immediately with plenty of soap-suds. 
S36/37:Wear suitable protective clothing and gloves. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
RIDADR: UN 2811 6.1/PG 2
WGK Germany: 3
F: 8-10-19

 Calcifediol (CAS NO.19356-17-3) is also named as (5Z,7E)-9,10-Seco-5,7,10(19)-cholestatrien-3beta,25-diol ; 25-Hydroxycholescalciferol ; 25-Hydroxyvitamin D ; 25-Hydroxyvitamin D3 ; 5,6-cis-25-Hydroxyvitamin D3 ; 5,6-trans-25-Hydroxycholescalciferol ; 5,6-trans-9,10-Seco-5,7,10(19)-cholestatrien-3beta,25-diol ; 9,10-Secocholesta-5,7,10(19)-triene-3beta,25-diol ; Calcidiol ; Calcifediolum ; Calcifediolum [INN-Latin] ; Calcifidiol ; Cholecalciferol, 25-hydroxy- ; Delakmin ; Didrogyl ; Hidroferol ; Ro 8-8892 ; Rovimix Hy-D ; U 32070 E ; UNII-T0WXW8F54E . It is the principal circulating form of vitamin D3.