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
B lymphocytes (B cells)
B cells are lymphocytes that play a large role in the humoral immune response. They are the surveillance cells of the immune system that circulate in the blood and lymph, making antibodies to invading pathogens when activated.
The isomeric form of carotene that is widely distributed in nature and most efficiently converted to vitamin A by the body. While excess vitamin A (as retinol) can be toxic to the body, residual beta-carotene is quickly eliminated.
BioMed Central (BMC)
An online journal that publishes peer-reviewed research across all areas of biology and medicine.
Blood level or blood calcidiol level
The amount of 25(OH)D (calcidiol) circulating in the blood. For proper health, blood calcidiol levels should begin at 125 nmol/L (50 ng/mL), with optimal ranges from 125–200 nmol/L (50–80 ng/mL). When someone refers to vitamin D blood level, they are referring to blood calcidiol level. see 25-hydroxyvitamin D test.
Bolus dose
An amount of IV medication administered rapidly to decrease the response time or to be used as a loading dose.
Bone mineral content (BMC)
Also called bone mass. The bone measurement used in growth studies and the single most important determinant of the risk of fracture.
Bone mineral density (BMD)
Measurement of the amount of calcium in bone.
Bone resorption
Removal of osseous tissue by osteoclasts. Bone resorption can be part of the normal balance of bone resorption and deposition or part of a pathologic process.

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