- Molecular NameCalcitriol
- Synonym1,25-(OH)2D3; 1,25-dihydroxycholecalciferol
- Weight416.646
- Drugbank_IDDB00136
- ACS_NO32222-06-3
- Show 3D model
- LogP (experiment)4.96
- LogP (predicted, AB/LogP v2.0)5.62
- pkaN/A
- LogD (pH=7, predicted)5.62
- Solubility (experiment)Insoluble
- LogS (predicted, ACD/Labs)(ph=7)-5.51
- LogSw (predicted, AB/LogsW2.0)0.01
- Sw (mg/ml) (predicted, ACD/Labs)0.0
- No.of HBond Donors3
- No.of HBond Acceptors3
- No.of Rotatable Bonds6
- TPSA60.69
- StatusFDA approved
- AdministrationN/A
- PharmacologyA form of Vitamin D3 with three alcohol groups. It increases gastrointestinal calcium absorption, stimulates osteoclastic calcium resorption from bone, facilitates the effect parathyroid hormone (PTH) has on bone resorption, and increases renal tubular absorption of calcium.
- Absorption_valueN/A
- Absorption (description)Rapidly absorbed from the intestine.
- Caco_2N/A
- Bioavailability61.0
- Protein binding99.9
- Volume of distribution (VD)N/A
- Blood/Plasma Partitioning ratio (D_blood)N/A
- MetabollsmThe first pathway involves 24-hydroxylase activity in the kidney; this enzyme is also present in many target tissues which possess the vitamin D receptor such as the intestine. The end product of this pathway is a side chain shortened metabolite, calcitroic acid. The second pathway involves the conversion of calcitriol via the stepwise hydroxylation of carbon-26 and carbon-23, and cyclization to yield ultimately 1a,25R(OH)2-26,23S-lactone D3. The lactone appears to be the major metabolite circulating in humans.
- Half life16.5 h
- ExcretionN/A
- Urinary Excretion<10
- Clerance0.43 ml/min/kg
- ToxicityLD50 (oral, rat) = 620 μg/kg; LD50 (intraperitoneal, rat) > 5 mg/kg; Overdose evident in elevated blood calcium levels causing symptoms of anorexia, nausea and vomiting, polyuria, polydipsia, weakness, pruritus, and nervousness, potentially with irreversible calcification of soft tissue in the kidney and liver.
- LD50 (rat)N/A
- LD50 (mouse)N/A