Vitamin D Council Glossary

# A B C D E F G H I J–K L M N O P R S T U V
Efficacy
Power or capacity to produce a desired effect.
Electrocardiogram (EKG or ECG)
A graphic record of the heart's action produced by an electrocardiograph and used for diagnostic purposes.
Electrocardiograph
Device that records the electrical activity of the heart over time.
Electrolyte
Substance that dissociates into ions (charged particles) in solution, making it capable of conducting electricity.
Endocrine
Cell signaling performed by the secretion of chemicals which are carried by the blood and tissue fluids to target cells.
Endocrine gland
Ductless glands that regulate physiological functions in the body by secreting hormones directly into the bloodstream.
Endocrine system
System of glands that release hormones directly into the circulatory system to help to control metabolic activity. The endocrine system controls slow, long-lasting responses to internal stimuli.
Endocrinologist
Doctor trained in diagnosis of diseases which affect your glands, and in treating complex conditions that involve many systems within the body.
Endocrinology
The science of hormone function which includes the study of conditions such as:
  • diabetes
  • thyroid diseases
  • metabolic disorders
  • over or under production of hormones
  • menopause
  • osteoporosis
  • hypertension
  • cholesterol (lipid) disorders
  • infertility
  • lack of growth (short stature)
  • cancers of the endocrine glands
Endocytic
see endocytosis.
Endocytosis
A process of cellular ingestion by which the plasma membrane folds inward to bring substances into the cell.
Endogenous
Produced or synthesized within the organism or system.
Endothelial cells
Cells which line the entire circulatory system, from the heart to the smallest capillary, and reduce turbulence in the blood flow.
Endorphin
Any of several morphine-like peptides naturally produced in the brain which bind to certain neuron receptors and have the effect of diminishing pain.
Endotoxemia
Presence of endotoxins in the blood, increasing risk of hemorrhages, necrosis of the kidneys, and shock.
Enzyme
A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism.
Ependymal cell
Cell which lines the ventricles (fluid-filled spaces in the brain).
Ependymoma
A rare type of glioma that develops from the ependymal cells in the brain and from the central canal of the spinal cord. Ependymomas can be found in any part of the brain or spine and in children are more common in the cerebellum.
Epidemic
Sudden outbreak of infectious disease or other health related event that occurs in numbers exceeding normal expectancy.
Epidemiological
Relating to the study of the causes, distribution, and control of disease in populations.
Epidemiological study
Statistical study on human populations in which the aim is to link human health effects to a specified cause.
Epidemiologist
Medical scientist who investigates and describes factors that influence the development of disease, disability, and other health outcomes.
Epidemiology
Study of diseases in populations of humans (or other animals) to determine associated risk factors and protective factors.
Epidermis
The upper (or outer layer) of the two main layers of cells that make up the skin.
Epithelial cells
Cells located throughout the body, a portion of which are used for secretion and make up specific parts of the body referred to as glands.
Epithelium
Tissue composed of a layer of cells.
Equipotent
Having equal effects or capacities.
Ergocalciferol
Vitamin D2. A vitamin D-like, patented drug that is not naturally present in the human body. Ergocalciferol is derived from fungal and plant sources by activating ergosterol with ultraviolet light, is only half as potent as cholecalciferol (real vitamin D), and may even block some of cholecalciferol's beneficial effects. It is more toxic and is the cause of most of the reported cases of vitamin D toxicity.
Ergometer
A device which measures the amount of energy or work performed.
Ergosterol
Precursor to ergocalciferol (Vitamin D2). A component of fungal cell membranes which serves the same function in plants that cholesterol does in animals.
Estrogen
Steroid hormone present in both men and women, usually at higher levels in women of reproductive age.
Etiology
Cause of a disease or abnormal condition.
Eukaryote
An organism, such as an animal, plant, fungus, or protist, whose cells are organized into complex structures enclosed within membranes.
Eukaryotic
see eukaryote.
Exocrine gland
Duct glands that secrete enzymes into ducts. Typical exocrine glands include sweat glands, salivary glands, mammary glands, stomach, prostrate, and liver.
Experimental autoimmune encephalomyelitis (EAE)
An experimental model of brain inflammation that mimics, to some degree, the inflammation that occurs in multiple sclerosis (MS).

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.