This site is intended for UK Healthcare Professionals only

UK/FLY/2023/2636 V4| October 2024

Prescribing information and adverse event reporting statement can be found in the footer

This site is intended for UK Healthcare Professionals only

UK/FLY/2023/2636 V4| October 2024

Prescribing information and adverse event reporting statement can be found in the footer

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The ABC of Vitamin D

Now available on demand - This event outlines the role of vitamin D within the human body, along with the effects of vitamin D deficiency on health. It explores the evidence base for the pharmacological management of vitamin D deficiency and examines the clinical benefits of different treatment options for hypovitaminosis D.

Importance of Vitamin D

Vitamin D is a fat-soluble vitamin that is present naturally in few foods, added to others, available as a dietary supplement or Prescribed Only Medicine (POM) and produced endogenously when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis.1 Vitamin D is an essential part of calcium and phosphate homeostasis,2 and skeletal health.3 It encompasses two vital forms of vitamin D: vitamin D3 (colecalciferol) and vitamin D2 (ergocalciferol).
Vitamin D2 is present in UV-exposed mushrooms and is produced from irradiation of yeast.3 In contrast, Vitamin D3 is synthesised within the human skin from 7-dehydrocholesterol or obtained through dietary sources, POM or supplements (Figure 2).4 Vitamin D plays a role in preventing the development of rickets, osteomalacia and osteoporosis.5 Particularly with the elderly population, the benefits of vitamin D can help prevent muscle weakness6, bone fractures7 and fragility.8
Figure 1: Images of colecalciferol, calcifediol and calcitriol

What is Domnisol® (calcifediol monohydrate)?

Domnisol is a medication prescribed for the treatment and prevention of vitamin D deficiency in adults. It belongs to a specific category of vitamin D compounds known as 25-hydroxyvitamin D. This compound is formed through the initial hydroxylation process of Vitamin D3, also known as colecalciferol, and acts as a precursor to the biologically active form of vitamin D within the body, known as calcitriol (Figure 1). Calcifediol plays an important role in maintaining optimal vitamin D levels for overall health and well-being and it is the major circulating form of vitamin D in the bloodstream. Calcifediol levels are commonly measured through blood tests to assess an individual vitamin D status.2,3 In the UK, calcifediol is available as an oral capsule called Domnisol. Domnisol is independent of hepatic 25-hydroxylation and thus is one step closer in the metabolic pathway to the biologically active vitamin D3. Domnisol’s hydroxyl group on carbon 25 provides it with improved hydrophilic properties compared to colecalciferol (vitamin D3) making it an ideal treatment for numerous patient groups.3,9

Figure 2: The Vitamin D pathway including calcifediol and the biologically active form of vitamin D

REFERENCES:

1. Vitamin D. Accessed June 12, 2023. https://www.nhsinform.scot/healthy-living/food-and-nutrition/eating well/vitamin-d 2. Fleet JC. The Role of Vitamin D in the Endocrinology Controlling Calcium Homeostasis. Mol Cell Endocrinol. 2017;453:36-45. doi:10.1016/j.mce.2017.04.008 3. Jodar E, Campusano C, de Jongh RT, Holick MF. Calcifediol: a review of its pharmacological characteristics and clinical use in correcting vitamin D deficiency. Eur J Nutr. 2023;62(4):1579-1597. doi:10.1007/s00394-023-03103-1 4. Calcium I of M (US) C to RDRI for VD and, Ross AC, Taylor CL, Yaktine AL, Valle HBD. Overview of Vitamin D. In: Dietary Reference Intakes for Calcium and Vitamin D. National Academies Press (US); 2011. Accessed June 12, 2023. https://www.ncbi.nlm.nih.gov/books/NBK56061/ 5. Office of Dietary Supplements - Vitamin D. Accessed June 12, 2023. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ 6. Janssen HC, Samson MM, Verhaar HJ. Vitamin D deficiency, muscle function, and falls in elderly people. The American Journal of Clinical Nutrition. 2002;75(4):611-615. doi:10.1093/ajcn/75.4.611 7. Bischoff-Ferrari HA, Willett WC, Wong JB, et al. Prevention of nonvertebral fractures with oral vitamin D and dose dependency: a meta-analysis of randomized controlled trials. Arch Intern Med. 2009;169(6):551-561. doi:10.1001/archinternmed.2008.600 8. Wang Q, Yu D, Wang J, Lin S. Association between vitamin D deficiency and fragility fractures in Chinese elderly patients: a cross-sectional study. Ann Palliat Med. 2020;9(4):1660-1665. doi:10.21037/apm-19-610 9. Pérez-Castrillón JL, Dueñas-Laita A, Brandi ML, et al. Calcifediol is superior to colecalciferol in improving vitamin D status in postmenopausal women: a randomized trial. J Bone Miner Res. 2021;36(10):1967-1978. doi:10.1002/jbmr.4387