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
National Institute of Mental Health (NIMH)
Largest scientific organization in the world dedicated to research focused on the understanding, treatment, and prevention of mental disorders and the promotion of mental health.
National Institutes of Health (NIH)
Federal health agengy and main medical research center in the United States. Part of the U.S. Department of Health and Human Services.
Doctor who uses natural remedies such as herbs and foods rather than surgery or synthetic drugs.
Physician who has been trained in the diagnosis and management of kidney disease.
Damage to, or disease of, the kidney.
Nerve Growth Factor (NGF)
A compound that stimulates and directs nerve growth.
Nervous system
Coordinates rapid responses to external stimuli as well as controls almost every organ system in the body through a series of positive and negative feedback loops. Made up of several subsystems: the Central, Peripheral, Somatic, and Autonomic Nervous Systems.
A branching extension from the neuron cell body such as a dendrite or axon.
Neuroendocrine cells
Cells found in the hypothalamus that are involved in the regulation of functions in the entire body, such as the reproductive system and responses to stress, temperature, and sleep.
Neuroendocrine system
Governs homeostasis by regulating hormone secretion from the pituitary gland.
Substance, other than a neurotransmitter, released by a neuron that transmits information to other neurons, altering their activities.
Pertaining to both nerves and muscles.
Any of the conducting cells of the nervous system.
Any steroid that is active in the brain.
Chemical used to communicate signals between a neuron and another cell.
Neurotrophic factors
Also called neurotrophins, neurotrophic factors are a family of proteins responsible for the growth and survival of neurons during development, and for maintaining adult neurons. Because neurotrophic factors are capable of making damaged neurons regrow their processes, they represent exciting possibilities for reversing devastating brain disorders including Alzheimer's, Parkinson's, and Lou Gehrig's disease.
Benign overgrowth of skin pigment forming cells called melanocytes on the skin surface.
National Health and Nutrition Examination Surveys. Surveys designed to assess the health and nutritional status of adults and children in the United States through interviews and direct physical examinations.
National Hospital Discharge Survey. A national probability survey designed to meet the need for information on characteristics of inpatients discharged from non-Federal short-stay hospitals in the United States.
Nitric oxide synthase (NOS)
One of the most regulated enzymes in biology, of which there are three known isoforms:
  • Neuronal NOS (nNOS or NOS1): located in nervous tissue in both the central nervous system and peripheral nervous system, performs a function in cell communication.
  • Inducible NOS (iNOS or NOS2): located in the immune system and the cardiovascular system, plays a role in immune defence against pathogens.
  • Endothelial NOS (eNOS or NOS3 or cNOS): generates nitric oxide in blood vessels and is involved with regulating vascular function.
NK cells
Cytotoxic lymphocytes which constitute a major component of the innate immune system. NK cells play a major role in the host-rejection of both tumours and virally-infected cells.
No observable adverse effect level. The highest tested dose or concentration of a substance at which no such adverse effect is found.
Non-Hodgkin's Lymphoma (NHL)
A group of many closely related cancers that affect the lymphatic system that is divided into two major subgroups: B cell lymphomas (which develop from abnormal B lymphocytes) and T cell lymphomas (which develop from abnormal T lymphocytes).
N-terminal atrial natriuretic peptide. A marker of salt sensitivity and predictor of congestive heart failure severity.
Nuclear hormone receptor
Ligand-activated transcription factor that regulates gene expression by interacting with specific DNA sequences upstream of its target genes. see vitamin D receptor.
Nucleic acid
Polymer of joined nucleotides whose function is to maintain, replicate, and express genetic information. The important nucleic acids are DNA and RNA.
Nucleotides are the single units that make up nucleic acids like RNA and DNA. They are literally the building blocks of life.

*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.