CAS number 19356-17-3 YesY
PubChem 5283731
ChemSpider 4938806 YesY
DrugBank DB00146
MeSH Calcifediol
Jmol-3D images Image 1
Molecular formula C27H44O2
Molar mass 400.64 g/mol
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Calcifediol (INN), also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D (abbreviated 25(OH)D),[1] is a prehormone that is produced in the liver by hydroxylation of vitamin D3 (cholecalciferol) by the enzyme cholecalciferol 25-hydroxylase. Calcifediol is then converted in the kidneys (by the enzyme 25(OH)D-1α-hydroxylase) into calcitriol (1,25-(OH)2D3), a secosteroid hormone that is the active form of vitamin D. It can also be converted into 24-hydroxycalcidiol in the kidneys via 24-hydroxylation.[2][3]


Blood test

In medicine, a 25-hydroxy vitamin D (calcidiol) blood test is used to determine how much vitamin D is in the body.[4] The blood concentration of calcidiol is considered the best indicator of vitamin D status.[5] It is the most sensitive measure,[6] though experts have called for improved standardization and reproducibility across different laboratories.[5] According to MedlinePlus, the normal range of calcidiol is 30.0 to 74.0 ng/mL.[4] The normal range varies widely depending on several factors, including age and geographic location. A broad reference range of 20–150 nmol/L (8-60 ng/ml) has also been suggested,[7] while other studies have defined levels below 80 nmol/L (32 ng/ml) as indicative of vitamin D deficiency.[8]

Clinical significance

Increasing calcidiol levels are associated with increasing fractional absorption of calcium from the gut up to levels of 80 nmol/L (32 ng/mL).[citation needed] Urinary calcium excretion balances intestinal calcium absorption and does not increase with calcidiol levels up to ~400 nmol/L (160 ng/mL).[9]

A study by Cedric F. Garland and Frank C. Garland of the University of California, San Diego analyzed the blood from 25,000 volunteers from Washington County, Maryland, finding that those with the highest levels of calcifediol had a risk of colon cancer that was one-fifth of typical rates.[10]

See also


  1. ^ "Nomenclature of Vitamin D. Recommendations 1981. IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN)" reproduced at the Queen Mary, University of London website. Retrieved 21 March 2010.
  2. ^ Bender, David A.; Mayes, Peter A (2006). "Micronutrients: Vitamins & Minerals". In Victor W. Rodwell; Murray, Robert F.; Harper, Harold W.; Granner, Darryl K.; Mayes, Peter A.. Harper's Illustrated Biochemistry. New York: Lange/McGraw-Hill. pp. 492–3. ISBN 0-07-146197-3.  Retrieved December 10, 2008 through Google Book Search.
  3. ^ Institute of Medicine (1997). "Vitamin D". Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, D.C: National Academy Press. pp. 254. ISBN 0-309-06403-1. 
  4. ^ a b ""25-hydroxy vitamin D test: Medline Plus". Retrieved 21 March 2010.
  5. ^ a b Heaney, Robert P (Dec 2004). "Functional indices of vitamin D status and ramifications of vitamin D deficiency". American Journal of Clinical Nutrition 80 (6): 1706S–9S. PMID 15585791. 
  6. ^ Institute of Medicine (1997), p. 259
  7. ^ Bender, David A. (2003). "Vitamin D". Nutritional biochemistry of the vitamins. Cambridge: Cambridge University Press. ISBN 0-521-80388-8.  Retrieved December 10, 2008 through Google Book Search.
  8. ^ Hollis BW (February 2005). "Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D". J Nutr 135 (2): 317–22. PMID 15671234. 
  9. ^ Kimball et al. (2004). "Safety of vitamin D3 in adults with multiple sclerosis". J Clin Endocrinol Metab 86 (3): 645–51. PMID 17823429. 
  10. ^ Maugh II, Thomas H. "Frank C. Garland dies at 60; epidemiologist helped show importance of vitamin D: Garland and his brother Cedric were the first to demonstrate that vitamin D deficiencies play a role in cancer and other diseases.", Los Angeles Times, August 31, 2010. Accessed September 4, 2010.

External links

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Look at other dictionaries:

  • calcifediol — Forma fisiológica de la vitamina D prescrita para el tratamiento de enfermedades metabólicas óseas asociadas a insuficiencia renal crónica. Diccionario Mosby Medicina, Enfermería y Ciencias de la Salud, Ediciones Hancourt, S.A. 1999 …   Diccionario médico

  • calcifediol — noun A prehormone which is produced by hydroxylation of vitamin D3 (cholecalciferol) in the liver …   Wiktionary

  • calcifediol — SYN: calcidiol. * * * cal·cif·e·di·ol (kal″sif ə diґol) 25 hydroxycholecalciferol. [USP] a preparation of this compound, used in the treatment of hypocalcemia, hypophosphatemia, rickets, and osteodystrophy associated with various… …   Medical dictionary

  • Cholecalciferol — Cholecalciferol …   Wikipedia

  • Calcidiol — Strukturformel Allgemeines Name Calcidiol Andere Namen Calcif …   Deutsch Wikipedia

  • Calcidiol — Chembox new ImageFile = Calcidiol2.svg ImageSize = IUPACName = ( 6R ) 6 [( 1R,3aR,4E,7aR ) 4 [( 2Z ) 2 [( 5S ) 5 Hydroxy 2 methylidene cyclohexylidene] ethylidene] 7a methyl 2,3,3a,5,6,7 hexahydro 1H inden 1 yl] 2 methyl heptan 2 ol OtherNames =… …   Wikipedia

  • ATC code A11 — is a division of the Anatomical Therapeutic Chemical Classification System and part of the A Alimentary tract and metabolism section.A11A Multivitamins, combinations*11AA Multivitamins with minerals:A11AA01 Multivitamins and iron:A11AA02… …   Wikipedia

  • Calcitriol — Systematic (IUPAC) name (1R,3S) 5 [2 [(1R,3aR,7aS) 1 [(2R) 6 hydroxy 6 methyl heptan 2 yl] 7a methyl 2,3,3a,5,6,7 hexahydro 1H inden 4 ylidene]ethylidene] 4 methylidene cyclohexane 1,3 diol …   Wikipedia

  • 25-OH-D3 — Strukturformel Allgemeines Name Calcidiol Andere Namen (6R) 6 [(1R,3aR,4E,7aR) 4 [(2Z) 2 [(5S) 5 Hydroxy 2 methyliden cycl …   Deutsch Wikipedia

  • ATC Code A11 — Une division du Code ATC A Tube digestif et métabolisme Sommaire 1 A11A Multivitamines, associations 1.1 A11AA Multivitamines et minéraux 1.2 A11AB Multivitamines, autres associations …   Wikipédia en Français

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