Published 11/1/2015
Terry Stanton

Study: Nearly All Trauma Patients Show Low Vitamin D Levels

Intervention with supplements proved successful

A study of patients in an urban trauma population found that more than 98 percent of those who had not already been taking vitamin D supplements exhibited hypovitaminosis D. In a subsequent group of trauma patients who were provided with vitamin D supplements, all patients who were adherent with them achieved normal vitamin D levels at 7 weeks.

The authors say their findings could point to vitamin D supplementation in trauma patients as a cost-efficient intervention to reduce the risk of future fragility fractures and nonunion.

The first phase of the study, which was presented at the 2015 annual meeting of the Orthopaedic Trauma Association by Brendan Andres, involved 62 skeletally mature patients (35 women, 27 men; mean age, 55 years) treated surgically by one traumatologist over 4 months for acute fractures of the pelvis or extremities. The patients' baseline calcium and vitamin D intake were recorded, and vitamin D levels were measured; the results were used to determine the prevalence of hypovitaminosis D.

All but two patients, who were taking supplements prior to injury, were deficient for vitamin D. The mean baseline level was 17.4 ng/mL (sufficient is > 30 ng/mL).

Subsequently, a second group of 144 patients (91 men, 53 women; mean age, 45 years) were treated by the same surgeon for acute fractures and served as the intervention group. Eleven patients in this group were taking supplements prior to injury; 80 percent of these patients had sufficient levels of vitamin D. As a result, the mean baseline vitamin D level was higher in this group—20.2 ng/mL. When patients previously taking supplements were removed from the calculation, the mean baseline vitamin D level dropped to 16.9 ng/mL.

All of the patients in the intervention group were prescribed twice daily calcium (600 mg) and vitamin D3 capsules (800 IU). Patients discharged to home received a free 6-month supply of calcium/D supplement. Vitamin D levels were obtained at time of injury and again after approximately 6 to 8 weeks of supplementation. Patients were surveyed in the outpatient clinic to determine adherence to the supplement, dietary intake of vitamin D, and exposure to the sun.

Of this group, 77 patients completed compliance surveys and had additional testing. After a mean of 7.0 weeks of supplementation, the mean vitamin D level (n = 74) was 36.7 ng/mL. This represented a statistically significant increase (P < 0.0001). After discharge, 79 percent reported adherence to supplement recommendations. All adherent patients had achieved normal vitamin D levels at follow-up. The most common reasons for nonadherence were forgetfulness and patient choice not to take the supplement.

Self-reported dairy consumption was minimal among those patients who completed the survey; 38 percent reported some daily consumption, and 32 percent reported approximately weekly consumption of dairy products. For self-reported exposure to sunlight, 61 percent of patients reported 15 minutes of sun exposure daily, and 92 percent reported using no sun protection.

Benefit for bones
The authors concluded that their study had implications for musculoskeletal health because vitamin D is a regulator of blood levels of calcium and phosphorus and controls intestinal absorption of calcium. "When dietary calcium is lacking," the authors wrote, "vitamin D, in conjunction with parathyroid hormone, will mobilize calcium from bone and enhance reabsorption within the kidney. Vitamin D also directly stimulates osteoblasts for bone synthesis, and it is essential for bone formation and healing."

They also identified possible impacts of low levels of vitamin D in the trauma population. "Hypovitaminosis D is pertinent in orthopaedic patient populations due to its link to osteomalacia, osteoporosis, poor bone and soft tissue healing, and higher rates of osteoporotic fractures when not sufficient. Further, hypovitaminosis D has been shown to decrease neuromuscular function, weaken muscles, and increase fall risk," they wrote.

"Previous studies have used a vitamin D and calcium supplement to raise vitamin D levels to beneficial thresholds, but few have focused on an orthopaedic trauma population," said Mr. Andres. A recent meta-analysis concluded that a vitamin D with calcium supplement was effective at raising vitamin D levels and reducing fall and secondary nonvertebral fracture risk in older patients.

The finding that all of the patients in the initial group who were not already on supplementation had vitamin D deficiency is "very alarming," the authors commented, "and has implications for public health, especially in light of an aging population with rising life span, and increasing annual healthcare expenditures in the United States for treatment of injury."

Vitamin D can be obtained from the sun, diet, and supplements. Although the primary source of vitamin D is the sun's ultraviolet rays, synthesis decreases with increasing age, latitude, sun protection, and melanin concentration. Even in sunny climates, vitamin D insufficiency occurs in up to 78 percent of patients.

The authors reported that vitamin D levels were measured under conditions in which patients would be most susceptible to insufficiency—during the winter in a location 41°N latitude. "Although seasonal trends could explain the higher prevalence rate observed in part 1 of our study," the authors wrote, "97 percent of the patients not taking baseline supplement in part 2 of our study also had hypovitaminosis D.

"Our findings suggest that a supplement is needed year round to maintain adequate vitamin D levels," they concluded. "Our data also suggest that hypovitaminosis D is prevalent despite some dietary intake and sun exposure in many patients."

The senior author of the study, Heather A. Vallier, MD, of Case Western Reserve University, said that at her center, orthopaedic patients are no longer routinely checked for vitamin D levels, but all patients are prescribed supplements, with a suggested dose of 1,000 IU to 2,000 IU of vitamin D per day.

"Further study is in order to determine cost-effectiveness of this intervention in terms of potential reduction of nonunion risk and reduction of lifetime fracture risk," she said.

Coauthors with Mr. Andres and Dr. Vallier of "Treatment of Hypovitaminosis in an Orthopaedic Trauma Population" are Benjamin R. Childs and Anna Wallace, MD. The authors' disclosure information can be accessed at www.aaos.org/disclosure

Terry Stanton is a senior science writer for AAOS Now. He can be reached at tstanton@aaos.org

Bottom Line

  • Vitamin D is a regulator of blood calcium and, as a direct stimulator of osteoblasts for bone synthesis, it is essential for bone formation and healing.
  • Among a population of orthopaedic trauma patients, all who were not taking a supplement were deficient in vitamin D.
  • In a subsequent group of trauma patients, all who were given vitamin D supplementation achieved normal levels of vitamin D.
  • Routine vitamin D supplementation may be a cost-effective way to achieve reduction of nonunion risk and reduction of lifetime fracture risk.