The association between vitamin D levels and recurrent group A streptococcal tonsillopharyngitis in adults

Objectives: To determine the association between recurrent group A streptococcal (GAS) tonsillopharyngitis and serum 25-hydroxy (25(OH)) vitamin D among adult subjects. Methods: Adult patients with tonsillopharyngitis between January 2007 and December 2009 were reviewed and identified retrospectively. Cases with a medical history of recurrent GAS tonsillopharyngitis were compared to age- and gender-matched individuals without a medical history of GAS tonsillopharyngitis. Recurrent tonsillopharyngitis was defined as three or more episodes of GAS tonsillopharyngitis per year for a period of two consecutive years. Results: Fifty-four cases with recurrent GAS tonsillopharyngitis and 50 controls were enrolled. There were no significant differences between cases and controls with regard to mean age (41 ± 13 vs. 42 ± 12 years; p= 0.7) and male gender (55% vs. 54%; p= 0.6). Mean serum levels of 25(OH) vitamin D among subjects with recurrent GAS tonsillopharyngitis were significantly lower from the controls (11.5 ng/ml ± 4.7 vs. 26 ng/ml ± 7; p= 0.001). Multiple regression analysis showed that a serum 25(OH) vitamin D level <20 ng/ml was associated with recurrent GAS tonsillopharyngitis (odds ratio 1.62, 95% confidence interval 1.51-1.76; p < 0.001). Conclusions: Our findings indicate a link between vitamin D deficiency and the recurrence of GAS tonsillopharyngitis.