Research presented at the 2012 Orthopaedic Trauma Association Annual Meeting finds that orthopaedic trauma patients commonly have low levels of vitamin D.

Low levels of vitamin D have been linked with fragility fractures and fracture nonunion, two conditions frequently seen by trauma surgeons. The literature on vitamin D deficiency among orthopaedic trauma patients, however, is sparse, according to presenter Brett D. Crist, MD, of the University of Missouri. Dr. Crist and his fellow researchers sought to determine the prevalence of vitamin D deficiency and insufficiency in this patient population.

Although often used interchangeably, vitamin D “insufficiency” and “deficiency” are defined differently. Vitamin D insufficiency is commonly defined as a 25-hydroxyvitamin D [25(OH)D] level of less than 32 ng/mL; deficiency is defined as a 25(OH)D level of less than 20 ng/mL. Thus, patients who are vitamin D deficient are a subset of patients who are vitamin D insufficient.

Retrospective chart review
The researchers conducted a retrospective chart review of 1,830 adult fracture patients treated at aLevel 1 trauma center by four orthopaedic traumatologists between Jan. 1, 2009, and Sept. 30, 2010. Inclusion criteria were acute fracture and an available 25(OH)D level.

“Vitamin D levels are typically based on a 25(OH)D serum test. Low levels of vitamin D are associated with increased parathyroid hormone expression, increased bone absorption, and decreased dietary calcium absorption,” explained Dr. Crist.

Patients younger than 18 years of age and those with the following known risk factors for vitamin D insufficiency were excluded:

• renal insufficiency (creatinine level of greater than 2 mg/dl)
• malabsorption syndrome
• gastrectomy
• active liver disease
• acute myocardial infarction
• alcoholism
• anorexia nervosa
• steroid dependency

Insufficiency prevalent
According to the National Institutes of Health, most Americans have blood levels of vitamin D that are lower than 30 ng/mL; almost no one has levels that are too high. In general, young people have higher blood levels of 25(OH)D than older people and males have higher levels than females. By race, non-Hispanic blacks tend to have the lowest levels and non-Hispanic whites the highest.

Among the 889 patients (487 females, 402 males; mean age: 53.8 years) who met the inclusion criteria for this study, the overall incidence of vitamin D insufficiency and deficiency was 77 percent (n = 688); the overall incidence of vitamin D deficiency alone was 39 percent (n = 347).

The researchers found no significant differences in the incidences of vitamin D insufficiency or deficiency based on age or sex (P < 0.05). interestingly, although patients aged 18 to 25 had the lowest levels of vitamin d deficiency and insufficiency of any age group, 55 percent were vitamin d insufficient and 29 percent were vitamin d deficient, noted dr. crist (>Table 1).

“The results showed that low vitamin D levels are prevalent among all adult orthopaedic trauma patients, not just the elderly,” he said. “In addition, seasonal variability was not a factor because levels were measured over a 21-month period.”

Because the study was retrospective, however, serum collections were not standardized and therefore levels may have been affected by acute phase reactants. Dr. Crist also noted the need for future studies that examine the impact of vitamin D insufficiency on fracture complications and prospective trials that measure the effectiveness of vitamin D insufficiency treatment.

Establishing the incidence of vitamin D insufficiency and deficiency in orthopaedic trauma patients is important to raise awareness and change screening and treatment patterns, the researchers noted.

“The take home is that vitamin D insufficiency is very easy to evaluate and easy to manage with supplements, with a low risk of side effects. For orthopaedic surgeons who treat fracture patients, it’s definitely something to think about,” said Dr. Crist. “Essentially, low vitamin D is easily identifiable and treatable and we shouldn’t ignore it. That can mean getting the test and either referring the results to the patient’s primary care provider or endocrinologist, or simply treating the patient yourself.”

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org

Dr. Crist’s coauthors of “Incidence of Vitamin D Deficiency in Orthopaedic Trauma Patients” are Michael A. Hood, MD; Gregory J. Della Rocca, MD, PhD; James P. Stannard, MD; David Volgas, MD; and Yvonne M. Murtha, MD.

Disclosures: Dr. Crist—Synthes, KCI, Medtronic, Amedica Corp., Orthopaedic Implant Co., Sonoma Orthopaedics, Wound Care Technologies, Depuy, A Johnson & Johnson Co., Zimmer, Journal of Orthopaedic Trauma (JOT), JAAOS, Your Orthopaedic Connection. Dr. Della Rocca—Synthes, Medtronic, LifeNet Health, Amedica Corp., The Orthopaedic Implant Co., Wound Care Technologies, Eli Lilly, Sonoma Orthopaedics, Journal of Bone and Joint Surgery – American; JOT; JAAOS. Dr. Stannard—KCI, Medtronic Sofamor Danek, Sonoma Orthopaedics, Smith & Nephew, Theime, Journal of Knee Surgery, OTA. Drs. Hood, Volgas, and Murtha – no conflicts.

Bottom Line

• Vitamin D deficiency and insufficiency affect nearly 1 billion people worldwide.
• Vitamin D deficiency and insufficiency have been associated with fragility fractures and fracture nonunion.
• Reports documenting incidences of vitamin D deficiency and insufficiency in the orthopaedic trauma population are sparse.
• This study found that low levels of vitamin D were prevalent among all orthopaedic trauma patients, not just the elderly.