Streptococcal tonsillopharyngitis recurrence linked to vitamin D deficiency

By Liam Davenport

There is a significant association between recurrent group A streptococcal (GAS) tonsillopharyngitis and vitamin D deficiency, say Israeli researchers who call for research into whether supplementation could prevent the condition.

Although vitamin D deficiency has been suggested as a possible factor in tonsillopharyngitis recurrence, it has not previously been tested in adults. William Nseir, from Holy Family Hospital in Nazareth, and colleagues therefore studied the records of 54 patients with GAS tonsillopharyngitis and 50 age- and gender-matched controls without a history of the disease.

The team notes in the International Journal of Infectious Diseases that recurrent GAS tonsillopharyngitis was defined as three or more episodes per year for 2 consecutive years. The normal range for serum 25-hydroxy (25(OH)) vitamin D levels was defined as 30-50 ng/mL, with vitamin D insufficiency defined as lower than 30 ng/mL and vitamin D deficiency as lower than 20 ng/mL.

Patients with recurrent GAS tonsillopharyngitis had significantly lower mean serum levels of 25(OH) vitamin D than controls, at 11.5 versus 26 ng/mL, and were significantly more likely to have vitamin D deficiency, at 92% versus 8%. In addition, patients had significantly greater serum C-reactive protein (CRP) levels than controls, at 4.9 versus 2.8 mg/L. There were no other significant differences between the two groups.

Multiple regression analysis taking into account body mass index, diabetes mellitus, and serum levels of iron, creatinine, and calcium revealed that a serum 25(OH) vitamin D level lower than 20 ng/mL and serum CRP levels higher than 3 mg/L were associated with recurrent GAS tonsillopharyngitis, at odds ratios of 1.62 and 1.57, respectively.

The researchers conclude that "recurrent GAS tonsillopharyngitis in adults could be related to vitamin D levels."

They note: "Because measurement of vitamin D levels is easily done and vitamin D supplements are readily obtainable and inexpensive, further studies are needed to assess whether this represents a causal association and whether vitamin D replacement therapy can prevent the recurrence of GAS tonsillopharyngitis."

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