Glossary

C-Reactive Protein (CRP)
An acute phase response protein that is only present in blood during (or after) trauma, infection, or serious illness.
Calcidiol
25(OH)D (25-hydroxyvitamin D). A prehormone in your blood that is produced in the liver from the metabolism of vitamin D3 cholecalciferol. When testing for vitamin D deficiency, this is the only form that should be tested for.
Calciferol
see Ergocalciferol.
Calcipotriol
Vitamin D analogue. Also referred to as Calcipotriene.
Calcitriol
1,25(OH)2D3 (1,25-dihydroxyvitamin D). Referred to as activated vitamin D, calcitriol is the most potent steroid hormone in the human body and has powerful anti-cancer properties. Calcitriol is made from calcidiol in the kidneys and other tissues and is also produced synthetically as an analogue. Calcitriol levels should never be used to determine if you are deficient in vitamin D.
Calcium
A metallic, bivalent element that is essential to living organisms and plays a key role in metabolism. Calcium is responsible for the growth, maintenance, and radiopacity of bone and is a factor in the production of lymphatic fluids. Vitamin D is crucial for calcium absorption.
Calmodulin (CaM)
Calcium-binding protein that binds to and regulates many different protein targets, thereby affecting many different cellular functions. Mediates processes such as metabolism, inflammation, apoptosis, muscle contraction, intracellular movement, nerve growth, short-term memory, long-term memory, and the immune response.
cAMP
Cathelicidin Antimicrobial Peptide gene. Direct target of the vitamin D receptor and an effector of innate immune response in mammals. Humans and mice have only one cathelicidin gene, as compared to domesticated mammals who have multiple.
Centers for Disease Control and Prevention (CDC)
One of the 13 major operating components of the United States Government's Department of Health and Human Services (HHS) whose mission is "to prevent and control infectious and chronic diseases, injuries, workplace hazards, disabilities, and environmental health threats."
Central Nervous System (CNS)
Largest part of the nervous system. Composed of the brain and spinal cord.
Cholecalciferol
Vitamin D3. Cholecalciferol is the naturally occurring form of vitamin D. It is a prehormone that is synthesized naturally in the skin by ultraviolet B irradiation of 7-dehydrocholesterol. Cholecalciferol is real vitamin D. All other compounds are either metabolic products or chemical modifications.
Cholesterol
A precursor for important steroid molecules such as bile salts, steroid hormones, and vitamin D.
Congestive Heart Failure (CHF)
A condition in which the heart is unable to adequately pump blood throughout the body and/or unable to prevent blood from "backing up" into the lungs.
Coronary atherosclerosis
The build up of plaque from substances such as cellular waste products, calcium, and fibrin in the inner lining of an artery, causing coronary heart disease.
Council for Responsible Nutrition (CRN)
Washington-based trade association representing ingredient suppliers and manufacturers in the dietary supplement industry.
CYP24
25-hydroxyvitamin D3-24-hydroxylase. Gene that encodes the mitochondrial protein which initiates the degradation of calcitriol, thereby regulating calcitriol levels and playing a role in calcium homeostasis and the vitamin D endocrine system.
CYP27B1
Gene that encodes the enzyme which regulates the level of calcitriol in the body and is important in calcium homeostasis. Mutations in this gene can result in vitamin D-dependent rickets type I.
Cytokine
A protein or peptide used as a signaling compound in organisms.
Cytotoxic
Toxic to cells.