Calcifediol
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Preferred IUPAC name
(1S,3Z)-3-[(2E)-2-{(1R,3aS,7aR)-1-[(2R)-6-Hydroxy-6-methylheptan-2-yl]-7a-methyloctahydro-4H-inden-4-ylidene}ethylidene]-4-methylidenecyclohexan-1-ol | |
Other names | |
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3D model (
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DrugBank | |
ECHA InfoCard
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100.039.067 |
IUPHAR/BPS |
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KEGG | |
MeSH | Calcifediol |
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CompTox Dashboard (EPA)
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Properties | |
C27H44O2 | |
Molar mass | 400.64 g/mol |
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H05BX05 (WHO) | |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 (abbreviated 25(OH)D3),
Calcifediol is strongly bound in blood by the vitamin D-binding protein.[5] Measurement of serum calcifediol is the usual test performed to determine a person's vitamin D status, to show vitamin D deficiency or sufficiency.[4][5] Calcifediol is available as an oral medication in some countries to supplement vitamin D status.[4][6][7]
Biology
Calcifediol is the precursor for calcitriol, the active form of vitamin D.
At a typical intake of cholecalciferol (up to 2000 IU/day), conversion to calcifediol is rapid. When large doses are given (100,000 IU), it takes 7 days to reach peak calcifediol concentrations.
Calcifediol is further hydroxylated at the 1-alpha-position in the kidneys to form 1,25-(OH)2D3, calcitriol.
Calcifediol is also converted into
Blood test for vitamin D deficiency
In medical practice, a blood test for 25-hydroxy-vitamin D, 25(OH)D, is used to determine an individual's vitamin D status.[11] The name 25(OH)D refers to any combination of calcifediol (25-hydroxy-cholecalciferol), derived from vitamin D3, and ercalcidiol (25-hydroxy-ergocalciferol),[1] derived from vitamin D2. The first of these (also known as 25-hydroxy vitamin D3) is made by the body, or is sourced from certain animal foods or cholecalciferol supplements. The second (25-hydroxy vitamin D2) is from certain vegetable foods or ergocalciferol supplements.[11] Clinical tests for 25(OH)D often measure the total level of both of these two compounds together, generally without differentiating.[12]
This measurement is considered the best indicator of overall vitamin D status.[11][13][14] US labs generally report 25(OH)D levels as ng/mL. Other countries use nmol/L. Multiply ng/mL by 2.5 to convert to nmol/L.[4]
This test can be used to diagnose vitamin D deficiency, and is performed in people with high risk for vitamin D deficiency, when the results of the test can be used to support beginning replacement therapy with vitamin D supplements.[4][15] Patients with osteoporosis, chronic kidney disease, malabsorption, obesity, and some other infections may be at greater risk for being vitamin D-deficient and so are more likely to have this test.[15] Although vitamin D deficiency is common in some populations including those living at higher latitudes or with limited sun exposure, the 25(OH)D test is not usually requested for the entire population.[15] Physicians may advise low risk patients to take over-the-counter vitamin D supplements in place of having screening.[15]
It is the most sensitive measure, though experts have called for improved standardization and reproducibility across different laboratories.[4][13] According to MedlinePlus, the recommended range of 25(OH)D is 20 to 40 ng/mL (50 to 100 nmol/L) though they recognize many experts recommend 30 to 50 ng/mL (75 to 125 nmol/L).[11] The normal range varies widely depending on several factors, including age and geographic location. A broad reference range of 20 to 150 nmol/L (8-60 ng/mL) has also been suggested,[16] while other studies have defined levels below 80 nmol/L (32 ng/mL) as indicative of vitamin D deficiency.[17]
Increasing calcifediol levels up to levels of 80 nmol/L (32 ng/mL) are associated with increasing the fraction of calcium that is absorbed from the gut.[13] Urinary calcium excretion balances intestinal calcium absorption and does not increase with calcifediol levels up to ~400 nmol/L (160 ng/mL).[18]
Supplementation
Calcifediol supplements have been used in some studies to improve vitamin D status.
Calcifediol may have advantages over cholecalciferol for the correction of vitamin D deficiency states.
In 2016, the FDA approved a formulation of calcifediol (Rayaldee) 60 microgram daily as a prescription medication to treat secondary hyperparathyroidism in patients with chronic kidney disease.[7]
Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles. [§ 1]
- ^ The interactive pathway map can be edited at WikiPathways: "VitaminDSynthesis_WP1531".
History
Research in the laboratory of
Research
Studies are ongoing comparing the effects of calcifediol with other forms of vitamin D including cholecalciferol in prevention and treatment of osteoporosis.[3][20]
References
- ^ PMID 7094913.
- ^ "Drug and medical device highlights 2018: Helping you maintain and improve your health". Health Canada. 14 October 2020. Retrieved 17 April 2024.
- ^ a b c d e f g h i "Vitamin D". Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis. 11 February 2021. Retrieved 14 March 2022.
- ^ a b c d e f g h i j k l m "Office of Dietary Supplements - Vitamin D". ods.od.nih.gov. 9 October 2020. Retrieved 31 October 2020.
- ^ PMID 24529992.
- ^ S2CID 14005489.
- ^ a b "Rayaldee (calcifediol) FDA Approval History - Drugs.com". Retrieved 4 March 2021.
- ^ PMID 31589774.
- ^ PMID 18541563.
- PMID 22446158.
- ^ a b c d "25-hydroxy vitamin D test: Medline Plus". Retrieved 4 March 2021.
- ^ "25HDN - Clinical: 25-Hydroxyvitamin D2 and D3, Serum". Mayo Clinic Labs. 2021. Retrieved 4 March 2021.
- ^ PMID 15585791.
- PMID 24690624.
- ^ ABIM Foundation, American Society for Clinical Pathology, retrieved August 1, 2013, which cites
- Sattar N, Welsh P, Panarelli M, Forouhi NG (January 2012). "Increasing requests for vitamin D measurement: costly, confusing, and without credibility". Lancet. 379 (9811): 95–6. S2CID 12669468.
- Bilinski KL, Boyages SC (July 2012). "The rising cost of vitamin D testing in Australia: time to establish guidelines for testing". The Medical Journal of Australia. 197 (2): 90. S2CID 45880893.
- Lu CM (May 2012). "Pathology consultation on vitamin D testing: clinical indications for 25(OH) vitamin D measurement". American Journal of Clinical Pathology. 137 (5). PMID 22645788., which cites
- Arya SC, Agarwal N (May 2012). "The measurement of vitamin D3 requires maintaining quality control". American Journal of Clinical Pathology. 137 (5): 832, author reply 833. PMID 22523224.
- Arya SC, Agarwal N (May 2012). "The measurement of vitamin D3 requires maintaining quality control". American Journal of Clinical Pathology. 137 (5): 832, author reply 833.
- Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. (July 2011). "Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline". The Journal of Clinical Endocrinology and Metabolism. 96 (7): 1911–30. PMID 21646368.
- Sattar N, Welsh P, Panarelli M, Forouhi NG (January 2012). "Increasing requests for vitamin D measurement: costly, confusing, and without credibility". Lancet. 379 (9811): 95–6.
- Google Book Search.
- PMID 15671234.
- PMID 17823429.
- ^ "Calcifediol". go.drugbank.com. Retrieved 7 March 2021.
- ^ PMID 31064117.
- PMID 4310770.
- PMID 4332591.