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
LDL cholesterol
Low density lipoprotein. Commonly referred to as "bad cholesterol" because high LDL levels are said to lead to cardiovascular disease.
Leukemia
Cancer of the blood or bone marrow characterized by abnormal proliferation of blood cells, usually leukocytes.
Leukocyte
White blood cells that are produced in the bone marrow. Leukocytes function as part of the immune system, helping in the defense against infectious disease and foreign materials.
Ligand
Molecule that binds specifically to a receptor site of another molecule.
Lipid
Any fat-soluble (hydrophobic), naturally-occurring molecule. Fatty-acids and their derivatives and sterol-containing metabolites, such as cholesterol, are lipids. Lipids have many functions including energy storage and cell signalling and serve as structural components of cell membranes.
Lipoprotein
A lipoprotein is a biochemical assembly that contains both proteins and lipids.
LOAEL
Lowest Observed Adverse Effect Level.
Lumisterol
Naturally occurring steroid compound that is part of the vitamin D family.
Lymph
Pale fluid that circulates (due to surrounding muscle activity) through the lymphatic system bathing tissues, maintaining fluid balance, and removing bacteria. Lymph contains lymphocytes and macrophages, the primary cells of the immune system.
Lymphatic System
Major component of the body's immune system that produces and transports lymph from tissues to the bloodstream. The lymphatic organs (spleen and thymus) and lymph nodes filter out bacteria and other particles the lymph takes up from body tissues.The lymph system interacts with every organ in the body and is a protector and a defense mechanism against infection, viruses, bacteria, fungi, and disease.
Lymphocyte
A type of white blood cell in the adaptive immune system which plays an important role in the body's defenses. There are two categories of lymphocytes: the large, granular lymphocytes, called natural killer cells (NK cells), and the small lymphocytes, called T cells and B cells.
Lymphoma
Lymphoma is a group of about 35 different cancers that affect the immune system cells called lymphocytes.

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