Alfacalcidol

Alfacalcidol
Names
	Preferred IUPAC name (1R,3S,5Z)-4-Methylidene-5-[(2E)-2-{(1R,3aS,7aR)-7a-methyl-1-[(2R)-6-methylheptan-2-yl]octahydro-4H-inden-4-ylidene}ethylidene]cyclohexane-1,3-diol
	Other names Alphacalcidol; 1-Hydroxycholecalciferol
Identifiers
CAS Number	41294-56-8 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:31186 ;
ChEMBL	ChEMBL32540 ;
ChemSpider	4445376 ;
DrugBank	DB01436 ;
ECHA InfoCard	100.050.253
KEGG	D01518 ;
PubChem CID	5282181;
UNII	URQ2517572 ;
CompTox Dashboard (EPA)	DTXSID0022569 ;
	InChI InChI=1S/C27H44O2/c1-18(2)8-6-9-19(3)24-13-14-25-21(10-7-15-27(24,25)5)11-12-22-16-23(28)17-26(29)20(22)4/h11-12,18-19,23-26,28-29H,4,6-10,13-17H2,1-3,5H3/b21-11+,22-12-/t19-,23-,24-,25+,26+,27-/m1/s1 Key: OFHCOWSQAMBJIW-AVJTYSNKSA-N ; InChI=1/C27H44O2/c1-18(2)8-6-9-19(3)24-13-14-25-21(10-7-15-27(24,25)5)11-12-22-16-23(28)17-26(29)20(22)4/h11-12,18-19,23-26,28-29H,4,6-10,13-17H2,1-3,5H3/b21-11+,22-12-/t19-,23-,24-,25+,26+,27-/m1/s1 Key: OFHCOWSQAMBJIW-AVJTYSNKBM;
	SMILES O[C@@H]1CC(\C(=C)[C@@H](O)C1)=C\C=C2/CCC[C@]3([C@H]2CC[C@@H]3[C@H](C)CCCC(C)C)C;
Properties
Chemical formula	C27H44O2
Molar mass	400.64 g/mol
Melting point	136 °C (277 °F; 409 K)
Solubility in water	0.016 g/100 mL
Pharmacology
ATC code	A11CC03 (WHO)
License data	EU EMA: by INN;
Legal status	UK: POM (Prescription only); EU: Rx-only;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Alfacalcidol (or 1-hydroxycholecalciferol) is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive.

Alfacalcidol has a weaker impact on calcium metabolism and parathyroid hormone levels than calcitriol; but significant effects on the immune system, including regulatory T cells. It is considered to be a more useful form of vitamin D supplementation, mostly due to its much longer half-life and lower kidney load. It is the most commonly prescribed vitamin D metabolite for patients with end stage renal disease, given that impaired renal function alters the ability to carry out the second hydroxylation step required for the formation of the physiologically active form of vitamin D, 1,25-dihydroxyvitamin D3. Alfacalcidol is an active vitamin D3 metabolite, and therefore does not require the second hydroxylation step in the kidney.