Alfacalcidol Explained

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^[1] and parathyroid hormone levels^[2] than calcitriol; but significant effects on the immune system, including regulatory T cells.^[3] It is considered to be a more useful form of vitamin D supplementation, mostly due to much longer half-life and lower kidney load.^[4] 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.^[5]

It was patented in 1971 and approved for medical use in 1978.^[6]

Trade names

Pharmaceutical trade names include AlphaD and One-Alpha.

Other animals

Used as a poultry feed additive, it prevents tibial dyschondroplasia and increases phytate bioavailability.^[7]

Notes and References

1. Cavalli L, Cavalli T, Marcucci G, Falchetti A, Masi L, Brandi ML . Biological effects of various regimes of 25-hydroxyvitamin D3 (calcidiol) administration on bone mineral metabolism in postmenopausal women . Clinical Cases in Mineral and Bone Metabolism . 6 . 2 . 169–73 . May 2009 . 22461169 . 2781231 .
2. Moe S, Wazny LD, Martin JE . Oral calcitriol versus oral alfacalcidol for the treatment of secondary hyperparathyroidism in patients receiving hemodialysis: a randomized, crossover trial . The Canadian Journal of Clinical Pharmacology . 15 . 1 . e36-43 . 2008 . 18192704 . 2013-12-04 . dead . https://web.archive.org/web/20141006072122/http://www.jptcp.com/cjcp07017_wazny_e36-e43v2-r101690 . 2014-10-06 .
3. Zold E, Szodoray P, Nakken B, Barath S, Kappelmayer J, Csathy L, Hajas A, Sipka S, Gyimesi E, Gaal J, Barta Z, Hallay J, Szegedi G, Bodolay E . 6 . Alfacalcidol treatment restores derailed immune-regulation in patients with undifferentiated connective tissue disease . Autoimmunity Reviews . 10 . 3 . 155–62 . January 2011 . 20868777 . 10.1016/j.autrev.2010.09.018 . 2437/180066 . free .
4. Nuti R, Bianchi G, Brandi ML, Caudarella R, D'Erasmo E, Fiore C, Isaia GC, Luisetto G, Muratore M, Oriente P, Ortolani S . 6 . Superiority of alfacalcidol compared to vitamin D plus calcium in lumbar bone mineral density in postmenopausal osteoporosis . Rheumatology International . 26 . 5 . 445–53 . March 2006 . 16283320 . 10.1007/s00296-005-0073-4 . 9931256 .
5. Ritzerfeld M, Klasser M, Mann H . Alfacalcidol in the therapy of renal bone disease . International Journal of Clinical Pharmacology and Therapeutics . 39 . 12 . 546–50 . December 2001 . 11770836 . 10.5414/cpp39546 .
6. Book: Fischer . Jnos . Ganellin . C. Robin . vanc . Analogue-based Drug Discovery . 2006 . John Wiley & Sons . 9783527607495 . XXX . en.
7. Web site: Vitamin Derivatives. vitaminderivatives.com. 14 April 2023.