Vitamin D Council Glossary

Observational study (Observational studies)

Study design that draws inferences about the possible effect of a treatment on subjects.

Occupational Safety and Health Administration (OSHA)

A branch of the U.S. Government's Department of Labor which sets and enforces standards of workplace safety.

OFELY study

Prospective study of bone loss determinants in women aged 30–95 yrs.

Osseous

Having to do with bone, consisting of bone, or resembling bone.

Osteoarthritis (Osteoarthrosis,degenerative joint disease)

Most common type of arthritis (usually among the aged) that affects only joint function and does not affect skin tissue, lungs, eyes, or blood vessels.

Osteoblast (Osteoblasts)

Bone-forming cell of the skeleton. Activated vitamin D regulates osteoblastic cell proliferation, differentiation, and mineralization of its extracellular matrix.

Osteocalcin

Noncollagenous protein found in bone and dentin that is manufactured by osteoblasts and is often used as a biomarker for the bone formation process.

Osteoclast (Osteoclasts)

Specialized bone cell that absorbs bone, allowing for the deposition of new bone and maintenance of bone strength.

Osteoclastic resorption (Bone resorption)

The opposite of bone formation. Involves hydrolysis of collagen and the dissolution of bone mineral by large multi-nucleated cells called osteoclasts.

Osteomalacia (Rickets)

Pain, weakness, and fragility of the bones due to defective bone mineralization, usually as a result of vitamin D deficiency. The name rickets is used when the condition occurs in children.

Osteopenia

A condition of decreased calcification or bone density which increases risk of developing osteoporosis.

Osteoporosis

Disease in which bones become fragile and more likely to break of which women are four times more likely than men to develop.