Vitamin D status, bone mineral density, and the development of radiographic osteoarthritis of the knee: The Rotterdam Study.

Objective: To study the association between baseline vitamin D status, bone mineral density (BMD), and the development of radiographic osteoarthritis (ROA) of the knee in a large population-based cohort of men and women.

Methods: A sample of 1248 subjects (728 women and 520 men) was drawn from the Rotterdam Study, a prospective population-based cohort study of the elderly. At baseline, vitamin D dietary intake was determined, and BMD and 25-hydroxy vitamin D (25(OH)D) serum levels were measured.

The epithelial Ca2+ channel TRPV5 is essential for proper osteoclastic bone resorption.

Bone remodeling involves the interplay of bone resorption and formation and is accurately controlled to maintain bone mass. Both processes require transcellular Ca(2+) transport, but the molecular mechanisms engaged remain largely elusive. The epithelial Ca(2+) channel TRPV5 is one of the most Ca(2+)-selective transient receptor potential (TRP) channels.