Absorption, Distribution and Excretion
Many vitamin D analogs are readily absorbed from the GI tract following oral administration if fat absorption is normal. The presence of bile is required for absorption of ergocalciferol and the extent of GI absorption may be decreased in patients with hepatic, biliary, or GI disease (e.g., Crohn's disease, Whipple's disease, sprue). Because vitamin D is fat soluble, it is incorporated into chylomicrons and absorbed via the lymphatic system; approximately 80% of ingested vitamin D appears to be absorbed systemically through this mechanism, principally in the small intestine. Although some evidence suggested that intestinal absorption of vitamin D may be decreased in geriatric adults, other evidence did not show clinically important age-related alterations in GI absorption of the vitamin in therapeutic doses. It currently is not known whether aging alters the GI absorption of physiologic amounts of vitamin D. /Vitamin D analogs/
After oral administration of calcitriol, there is about a 2-hour lag-time before calcium absorption in the GI tract increases. Maximal hypercalcemic effect occurs in about 10 hours, and the duration of action of calcitriol is 3-5 days.
Time to peak serum concentration: Oral: Approximately 3 to 6 hours.
The primary route of excretion of vitamin D is the bile; only a small percentage of an administered dose is found in urine. /Vitamin D/
For more Absorption, Distribution and Excretion (Complete) data for 1,25-DIHYDROXYCHOLECALCIFEROL (10 total), please visit the HSDB record page.

---

Metabolism / Metabolites
Calcitriol is the active form of vitamin D3 (cholecalciferol). The natural or endogenous supply of vitamin D in man mainly depends on ultraviolet light for conversion of 7-dehydrocholesterol to vitamin D3 in the skin. Vitamin D3 must be metabolically activated in the liver and the kidney before it is fully active on its target tissues. The initial transformation is catalyzed by a vitamin D3-25-hydroxylase enzyme present in the liver, and the product of this reaction is 25-(OH)D3 (calcifediol). The latter undergoes hydroxylation in the mitochondria of kidney tissue, and this reaction is activated by the renal 25-hydroxyvitamin D3-1-a-hydroxylase to produce 1,25-(OH)2D3 (calcitriol), the active form of vitamin D3.
1,25-Dihydroxycholecalciferol (calcitriol) and 1,25-dihydroxyergocalciferol appear to be metabolized to their respective trihydroxy metabolites (i.e., 1,24,25-trihydroxycholecalciferol, 1,24,25-trihydroxyergocalciferol) and to other compounds. The principal metabolite excreted in urine is calcitroic acid, which is more water soluble. Although all the metabolites of cholecalciferol and ergocalciferol have not been identified, hepatic microsomal enzymes may be involved in degrading metabolites of ergocalciferol and cholecalciferol.
Calcitriol /(1,25-dihydroxy-vitamin D)/ is hydroxylated to 1,24,25-(OH)3-D by a renal hydroxylase that is induced by calcitriol and suppressed by those factors that stimulate the 25-OHD-1-alpha-hydroxylase. This enzyme also hydroxylates 25-OHD to form 24,25-(OH)2D. Both 24-hydroxylated compounds are less active than calcitriol and presumably represent metabolites destined for excretion. Side chain oxidation of calcitriol also occurs.
To evaluate the relation between daily and fasting urinary calcium excretion and serum 1,25-dihydroxyvitamin D (II) concentrations, 6 healthy men were studied during control and during chronic oral calcitrol (I) administration (0.6, 1.2, or 1.8 nmols every 6 hours for 6-12 days) while they ate normal and low calcium diets (19.2 or 4.2 mmols Ca/day). Daily urinary calcium excretion was directly related to serum II concentrations, but increased more while subjects ate the normal calcium diet than when eating the low calcium diet. During I and ingestion of the low calcium diet, daily urinary calcium excretion averaged 7.32 mmole/day, exceeding the dietary calcium intake. Fasting urinary calcium/creatinine exceeded 0.34 mmol/mmol (the upper limit of normal) on either diet. When serum II concentrations are elevated, a high fasting urinary calcium/creatinine or high daily urinary calcium excretion, even on a low calcium diet, is insufficient criteria for the documentation of a renal calcium leak.
For more Metabolism/Metabolites (Complete) data for 1,25-DIHYDROXYCHOLECALCIFEROL (7 total), please visit the HSDB record page.

---

Biological Half-Life
Plasma half-life: 3 to 6 hours.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Calcitriol is the normal physiologically active form of vitamin D, 1,25-dihydroxyvitamin D. Several women with hypocalcemia have successfully breastfed during breastfeeding, with sometimes fluctuating serum calcium levels. Limited data indicate that its use in nursing mothers in appropriately adjusted doses does not affect the breastfed infant. If the mother requires calcitriol, it is not a reason to discontinue breastfeeding. Calcitriol and calcium dosage requirements are usually reduced during lactation in women with hypoparathyroidism.
◉ Effects in Breastfed Infants
A woman with hypoparathyroidism breastfed her infant from week 1 to week 32 postpartum while taking calcitriol. The dose was initially 0.5 mcg daily, but was decreased to 0.25 mcg daily after 8 weeks. The infant thrived during breastfeeding and had normal serum calcium levels at 1 and 3 weeks and 3 months of age.
A woman breastfed infants after two pregnancies while taking calcitriol in doses of 0.75 and 1 mcg daily. There were no reports of adverse reactions.
A woman breastfed her newborn infant for 9 days while taking calcitriol 0.5 mcg three times daily. Calcitriol was stopped at that time because of hypercalcemia, but restarted at 40 days postpartum in low doses that were gradually increased until the prepregnancy dosage of 1.5 mcg daily was reached just before weaning at 12.5 months postpartum.
A woman with discoid lupus was taking calcitriol 0.25 mcg every 2 days and several other medications concurrently. Her infant was breastfed for 12 months and followed up at 15 months of age. No adverse effects were reported during breastfeeding and the infant was growing and developing normally at 15 months of age.
A nursing mother with autosomal dominant hypoparathyroidism type 1 was treated with teriparatide for 8 months postpartum then calcitriol 0.5 mcg twice daily was substituted. She breastfed her infant exclusively for 6 months then with supplementation to 1 year. Her infant had no change in serum calcium when maternal calcitriol was begun. The mother began weaning at 11 months and at 1 year of age weaning was complete. Growth and development were normal at 1.5 years of age.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

[1]. (2000) The in vitro effect of calcitriol on parathyroid cell proliferation and apoptosis. J.Am.Soc.Nephrol. 11 1865. Beer and Myrthue (2004).

[2]. Calcitriol in cancer treatment: from the lab to the clinic. Mol.Cancer Ther. 3 373.

[3]. Nijenhuis et al (2006) The novel vitamin D analog ZK191784 as an intestine-specific vitamin D antagonist. FASEB J. 20 1589.

[4]. Krishnan AV, Swami S, Feldman D.Equivalent anticancer activities of dietary vitamin D and calcitriol in an animal model of breast cancer: Importance of mammary CYP27B1 for treatment and prevention.J Steroid Biochem Mol Biol. 2012 Aug 23.

[5]. Alkharfy KM, Al-Daghri NM, Yakout SM, Ahmed M.Calcitriol Attenuates Weight-Related Systemic Inflammation and Ultrastructural Changes of the Liver in a Rodent Model.Basic Clin Pharmacol Toxicol. 2012 Aug 21.

Mechanism of Action
Ergocalciferol and doxercalciferol (1-hydroxyergocalciferol); cholecalciferol and calcifediol (25-hydroxycholecalciferol); and dihydrotachysterol in their activated forms (1,25-dihydroxyergocalciferol; 1,25-dihydroxycholecalciferol [calcitriol]; and 25-hydroxydihydrotachysterol; respectively), along with parathyroid hormone and calcitonin, regulate serum calcium concentrations; in addition to conversion to the active 1,25-dihydroxycholecalciferol, calcifediol also has intrinsic activity.
Calcitriol (activated vitamin D) enhances the efficiency of intestinal calcium absorption along the entire small intestine, but principally in the duodenum and jejunum. Calcitriol also enhances phosphorus absorption along the entire small intestine, but principally in the jejunum and ileum. The activated forms of ergocalciferol, doxercalciferol, and cholecalciferol may have a negative feedback effect on parathyroid hormone (PTH) production.
Calcitriol appears to act in intestine in manner that is analogous to the way steroid hormones such as estrogens act on target tissues. ... Cytosol of chicken intestinal cells contains a 3.7 S protein that binds calcitriol specifically and with high affinity. Formation of complex with this receptor facilitates transfer of calcitriol to nuclear chromatin. ... Calcitriol stimulates synthesis of RNA and at least two proteins in intestinal mucosa, alkaline phosphatase and a calcium-binding protein. ... It was proposed that the calcium-binding protein is involved in transport of calcium. ... /However/, it has been reported that calcitriol-induced stimulation of intestinal transport of phosphate precedes that of calcium, and it is possible that primary effect of the vitamin is on phosphate rather than calcium transport.
The effects of 1,25-dihydroxyvitamin D3 (I) on the human promyelocytic leukemia cell line HL-60 were investigated. I induces the differentiation of HL-60 into mono- and multinucleated macrophage-like cells. Phenotypic change is evident within 24 hours and reaches a plateau at 72-96 hours of incubation. The changes are metabolite-specific and include adherence to substrate, acquisition of the morphological features of mature monocytes, a 4 to 6-fold enhancement in lysozyme synthesis and secretion, increase in the fraction of alpha-naphthyl acetate monocyte-associated cell surface antigens. Treated HL-60 cells acquire the capacity to bind and degrade bone matrix, 2 of the essential functional characteristics of osteoclasts and related bone-resorbing cells. Evidently, vitamin D3 enhances bone resorption and osteoclastogenesis in vivo by promoting the differentiation of precursor cells.
For more Mechanism of Action (Complete) data for 1,25-DIHYDROXYCHOLECALCIFEROL (6 total), please visit the HSDB record page.

C27H44O3

416.63646

422.367

78782-99-7

Calcitriol;32222-06-3

2524

White to off-white solid powder

111-115 °C

5.704

60.69

3

3

6

30

688

0

GMRQFYUYWCNGIN-UHFFFAOYSA-N

InChI=1S/C27H44O3/c1-18(8-6-14-26(3,4)30)23-12-13-24-20(9-7-15-27(23,24)5)10-11-21-16-22(28)17-25(29)19(21)2/h10-11,18,22-25,28-30H,2,6-9,12-17H2,1,3-5H3

5-[2-[1-(6-hydroxy-6-methylheptan-2-yl)-7a-methyl-2,3,3a,5,6,7-hexahydro-1H-inden-4-ylidene]ethylidene]-4-methylidenecyclohexane-1,3-diol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 该产品在溶液状态不稳定，请现配现用。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~50 mg/mL (~118.30 mM)

注意: 如下所列的是一些常用的体内动物实验溶解配方，主要用于溶解难溶或不溶于水的产品（水溶度<1 mg/mL）。 建议您先取少量样品进行尝试，如该配方可行，再根据实验需求增加样品量。

---

注射用配方1: DMSO : Tween 80： Saline = 10 : 5 : 85 (如： 100 μL DMSO → 50 μL Tween 80 → 850 μL Saline)
*生理盐水/Saline的制备：将0.9g氯化钠/NaCl溶解在100 mL ddH ₂ O中，得到澄清溶液。
注射用配方 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL DMSO → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)
注射用配方 3: DMSO : Corn oil = 10 : 90 (如： 100 μL DMSO → 900 μL Corn oil)
示例: 以注射用配方 3 (DMSO : Corn oil = 10 : 90) 为例说明, 如果要配制 1 mL 2.5 mg/mL的工作液, 您可以取 100 μL 25 mg/mL 澄清的 DMSO 储备液，加到 900 μL Corn oil/玉米油中, 混合均匀。

View More

注射用配方 4: DMSO : 20% SBE-β-CD in Saline = 10 : 90 [如：100 μL DMSO → 900 μL (20% SBE-β-CD in Saline)]
*20% SBE-β-CD in Saline的制备（4°C，储存1周）：将2g SBE-β-CD (磺丁基-β-环糊精) 溶解于10mL生理盐水中，得到澄清溶液。
注射用配方 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (如： 500 μL 2-Hydroxypropyl-β-cyclodextrin (羟丙基环胡精)→ 500 μL Saline)
注射用配方 6: DMSO : PEG300 : Castor oil : Saline = 5 : 10 : 20 : 65 (如： 50 μL DMSO → 100 μL PEG300 → 200 μL Castor oil → 650 μL Saline)
注射用配方 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (如： 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
注射用配方 8: 溶解于Cremophor/Ethanol (50 : 50), 然后用生理盐水稀释。
注射用配方 9: EtOH : Corn oil = 10 : 90 (如： 100 μL EtOH → 900 μL Corn oil)
注射用配方 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL EtOH → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)

---

口服配方 1: 悬浮于0.5% CMC Na (羧甲基纤维素钠)
口服配方 2: 悬浮于0.5% Carboxymethyl cellulose (羧甲基纤维素)
示例: 以口服配方 1 (悬浮于 0.5% CMC Na)为例说明, 如果要配制 100 mL 2.5 mg/mL 的工作液, 您可以先取0.5g CMC Na并将其溶解于100mL ddH2O中，得到0.5%CMC-Na澄清溶液；然后将250 mg待测化合物加到100 mL前述 0.5%CMC Na溶液中，得到悬浮液。

View More

口服配方 3: 溶解于 PEG400 (聚乙二醇400)
口服配方 4: 悬浮于0.2% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 5: 溶解于0.25% Tween 80 and 0.5% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 6: 做成粉末与食物混合

---

注意: 以上为较为常见方法，仅供参考， InvivoChem并未独立验证这些配方的准确性。具体溶剂的选择首先应参照文献已报道溶解方法、配方或剂型，对于某些尚未有文献报道溶解方法的化合物，需通过前期实验来确定（建议先取少量样品进行尝试），包括产品的溶解情况、梯度设置、动物的耐受性等。

---

请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。