The active natural hormonal form of
vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
is
1,25-dihydroxyvitamin D (1,25(OH)2D). This molecule and other naturally occurring forms of vitamin D, including its precursors and metabolites, have been modified to synthesize
pharmaceuticals
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...
with potentially greater, or selective, therapeutic actions.
Types
These include:
*
Alfacalcidol
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 and parathyroid hormone levels than calcitriol, howev ...
*
Calcipotriol
Calcipotriol, also known as calcipotriene, is a synthetic derivative of calcitriol, a form of vitamin D. It is used in the treatment of psoriasis. It is safe for long-term application in psoriatic skin conditions.
It was patented in 1985 and a ...
(calcipotriene)
*
Doxercalciferol
Doxercalciferol (or 1-hydroxyergocalciferol, trade name Hectorol) is drug for secondary hyperparathyroidism and metabolic bone disease. It is a synthetic analog of ergocalciferol (vitamin D2). It suppresses parathyroid synthesis and secretion.
...
*
Falecalcitriol
Falecalcitriol (INN) is an analog of calcitriol
Calcitriol is the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It is a hormone which binds to and activates the vitamin D receptor in ...
*
Paricalcitol
Paricalcitol (chemically it is 19-nor-1,25-(OH)2-vitamin D2. Marketed by Abbott Laboratories under the trade name Zemplar) is a drug used for the prevention and treatment of secondary hyperparathyroidism (excessive secretion of parathyroid horm ...
*
Tacalcitol
Tacalcitol (1,24-dihydroxyvitamin D3) is a synthetic vitamin D3 analog. Tacalcitol is marketed under several names, including Curatoderm and Bonalfa.
It is on the World Health Organization's List of Essential Medicines.
Mechanism
Tacalcitol re ...
Mechanisms
These modified vitamin D analogues have side chain or other modifications. They aim to reduce the classical renal and intestinal effects of calcitriol on
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
and
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
homeostasis, from its effects on other biologic processes.
They target
cell proliferation
Cell proliferation is the process by which ''a cell grows and divides to produce two daughter cells''. Cell proliferation leads to an exponential increase in cell number and is therefore a rapid mechanism of tissue growth. Cell proliferation re ...
and
differentiation, especially in skin, or other effects in the parathyroid gland (secondary
hyperparathyroidism
Hyperparathyroidism is an increase in parathyroid hormone (PTH) levels in the blood. This occurs from a disorder either within the parathyroid glands (primary hyperparathyroidism) or as response to external stimuli (secondary hyperparathyroidism). ...
) or bone cells.
[
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References
{{Vitamin D receptor modulators
Drugs
Vitamin D