Review Question - QID 3538

This patients history and radiographs demonstrate a low energy distal radius fracture, which are common in middle and older age females with underlying osteoporosis. 25-hydroxy cholecalciferol (25 OH vitamin D) would be the most appropriate laboratory test in this patient who sustained a fall from a standing height (low energy). Vitamin D3 is converted to 25-OH vitamin D in the liver and then becomes the active hormone form, 1,25-OH vitamin D, or the inactive hormone form, 24,25-OH vitamin D, in the kidney. Osteomalacia is a metabolic bone disease where defective mineralization results in a large amount or unmineralized osteoid and is a qualitative defect as opposed to a quanitative defect like osteoporosis/osteopenia.

Pieper et al conducted a study looking at the values of 25-OH vitamin D in 1800 patients that recently sustained a hip fracture. They found that 51% of the patients were at or below the clinically meaningful threshold of 15 ng/mL. They concluded that physicians should be encouraged to check and monitor patients' serum levels of 25-OH vitamin D.

Binkley et al present a review recommending selective 25-OH vitamin D lab testing in patients. They report that barriers to universal use include the presence of 2 forms of vitamin D- ergocalciferol (D2) and cholecalciferol (D3), as well as the hydrophobic nature of vitamin D.

The review by Templeton discusses the many factors that can lead to osteopenia including eating disorders, smoking, alcoholism, endocrinopathies, GI disease, hepatobiliary disease, and corticosteroids. Peak bone mass is attained before 30 years of age, and failure to attain adequate bone mass at this time is one of the main causes in the development of osteoporosis.