SAN FRANCISCO – Only one-quarter of patients who were informed by mail to take vitamin D because of insufficient levels found in a blood test met their target of at least 30 ng/mL 6 months later, according to a chart review.
This less-than-ideal compliance among 338 osteopenic patients in a University of Toronto osteoporosis program may be partly attributable to the fact that the importance of the treatment wasn’t adequately addressed while the patients were in the clinic.
Dr. Vithika Sivabalasundaram
After blood tests there, 265 patients (78%) were mailed a form letter telling them that they had insufficient vitamin D levels, defined as 20-29 ng/mL, and to take 4,000 IU/day for 3 months and then 2,000 IU/day thereafter.
Meanwhile, 73 (22%) received a letter telling them they were deficient, with levels of less than 20 ng/mL, and to take one 50,000 IU pill per week and 2,000 IU/day for 3 months, then switch to 2,000 IU/day.
"We were recommending fairly high doses of vitamin D, and that may have been intimidating," especially for a largely asymptomatic condition. "There was no chance really for them to discuss face-to-face with a clinician what their vitamin D status meant, and what treatment entailed," lead investigator Dr. Vithika Sivabalasundaram, an internal medicine resident at the university, said at the Endocrine Society’s annual meeting.
Perhaps not surprisingly, only half (169) of the patients followed through with repeat blood tests after 6 months, as instructed. Of those, just 56% (95) met the target of at least 30 ng/mL. The others (74) were largely unchanged or actually lost ground.
The lesson is probably that "we need to inform our patients of the benefits of vitamin D on bone health, and that there’s fairly low toxicity associated with taking vitamin D," Dr. Sivabalasundaram said.
To that end, when patients get their blood drawn in the clinic, they’re now "informed that they might be placed on this vitamin D protocol, so when they receive the letter, they are not surprised by it and they understand what it means. That wasn’t done before. We are [also] having a nurse phone [patients] to discuss their vitamin D status and answer their questions. We are developing an information pamphlet" as well, and plan to translate the letter into other languages, she said, adding that "right now, we are just sending [it] out in English," which may be a problem for the clinic’s multicultural population.
The only predictor of hitting the 30 ng/mL mark in the study was how soon after 6 months patients got their blood checked, which was probably a surrogate for how seriously they took the protocol, Dr. Sivabalasundaram said.
Baseline vitamin D status and use of glucocorticoids didn’t predict success, nor did past osteoporotic fractures. "We thought that would motivate patients, but we didn’t see that," she said.
Patients with malabsorption syndrome were less likely to hit the mark, as were obese patients, "which makes sense because vitamin D is sequestered into fat cells," she said.
Patients were about 60 years old on average, mostly women, and mostly white.
Dr. Sivabalasundaram said that she had no conflicts to disclose. One of her coinvestigators has been a speaker and advisory group member for several pharmaceutical companies.