ORLANDO – Daily oral treatment with a vitamin D supplement significantly improved the ability of fluticasone nasal spray to relieve the total, daytime symptoms of seasonal rhinitis in a pilot, placebo-controlled study of 35 patients.

Two weeks of daily treatment with 4,000 IU of a standard, over-the-counter vitamin D pill also produced a strong trend toward improving the impact of a standard fluticasone nasal spray on nasal symptoms, and improved rhinoconjunctivitis quality of life, James Lane reported at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.

But because the study population was so small, the next step has to be an attempt to repeat the result in a larger number of patients, said Mr. Lane, a researcher in the department of surgery at the University of Chicago.

"We were not expecting vitamin D to look this good. The spread [between vitamin D treatment and placebo] was convincing and surprising; the differences we saw at days 2 and 3 were huge. We need to do it again," said Dr. Fuad M. Baroody, a professor of surgery and pediatrics at the University of Chicago and the senior investigator of the study.

"This was a shot in the dark, to see if there was any chance of it working for rhinitis. I hope we’ll get funding [from the National Institutes of Health] because industry won’t fund this," Dr. Baroody said in an interview. He and his associates tested vitamin D because of prior evidence that it can improve immune function.

He said that he has submitted a proposal to the NIH for a four-arm follow-up study: vitamin D alone, fluticasone alone, both agents together, and a double-placebo group. Dr. Baroody added that he has consulted a statistician who calculated that for a four-group study like this that involves multiple between-group comparisons, he would need to enroll about 150 patients into each arm – 600 patients in total – to produce adequate statistical power.

"There is no way we could do that by ourselves. If the government doesn’t fund it, it dies here," he said.

The study enrolled patients who were 18-45 years old and had at least a 2-year history of seasonal allergic rhinitis to tree, grass, or ragweed pollen during the pollen seasons of 2010 and 2011. The patients also needed to have a positive skin-test reaction to one of the pollen types, and had to show at least a 35% improvement in their peak nasal flow following treatment with oxymetazoline, a decongestant.

The researchers had all patients self-administer 100-mcg fluticasone propionate nasal spray into each nostril once daily, and randomized patients to daily oral treatment with 4,000 IU of vitamin D or placebo for 14 days.

The enrolled patients had an average age of about 28 years, with roughly equal numbers of men and women. At baseline, their average level of serum vitamin D was about 30 ng/mL. By the end of the study, the average vitamin D level of the patients randomized to take a daily vitamin D pill had risen to 37 ng/ml, while the average level in the placebo patients had not changed from baseline.

After 2 weeks in the study, the daytime total-symptom score throughout the study period fell by an average of 3.7 points in the placebo group and by 6.9 points in the patients taking vitamin D, a significant statistical difference. The 24-hour, nasal-symptom score throughout the study fell by an average of 7.6 points in the placebo patients and by 11.3 points in the vitamin D group, a difference that approached significance. Both the total symptom scores and nasal symptom scores fell dramatically lower in the vitamin D patients during the first week of the study and then remained low during the second week. In contrast, scores fell more gradually in the placebo patients, but by the final, 14th day of the study average scores in the placebo patients approached those of the patients on vitamin D. This pattern suggested that vitamin D helped hasten patient responses to fluticasone, Dr. Baroody said.

The researchers also measured the patients’ rhinoconjunctivitis quality of life at baseline and after 2 weeks on treatment. This measure fell by an average of 2.0 units in the placebo patients and by an average of 2.5 units in the patients who took vitamin D. With this metric, a reduction of at least 0.5 units is considered clinically meaningful. The results therefore showed that while the patients taking fluticasone alone had a meaningful quality of life improvement, the incrementally better improvement in patients also taking vitamin D was even more clinically meaningful, although the between-group difference of 0.5 units was not significant.

Mr. Lane and Dr. Baroody said that they had no relevant disclosures.

Vitamin D May Boost Fluticasone's Allergic Rhinitis Effect