Vitamin D and tonsil disease--preliminary observations.

OBJECTIVE: To estimate the prevalence of 25(OH) vitamin D deficiency in children undergoing (adeno)tonsillectomy. METHODS: From 1st November 2008 to 20th December 2008, 33 children aged from 4 to 16 and resident in Auckland, New Zealand (latitude 36° 52' S) undergoing (adeno)tonsillectomy for difficulty breathing/sleep apnoea and/or recurrent tonsillitis had 25(OH) vitamin D, iron and zinc levels measured. RESULTS: Of the 32 patients who had 25(OH) vitamin D levels measured, 15.6% were vitamin D deficient (25(OH) vitamin D<50nmol/L), and 78% had levels, <75nmol/L. 25(OH) vitamin D level was inversely correlated with Fitzpatrick skin type (Spearman's rho=-0.713, p<0.01), body mass index (BMI) (Spearman's rho=-0.434, p=0.013) and tonsil size (Spearman's rho=-0.417, p=0.017). However regression modeling demonstrated that only Fitzpatrick skin type (β=-0.687, p=0.001) and BMI (β=-0.256, p=0.044) were significant predictors of vitamin D levels (R(2)=0.572). CONCLUSIONS: Seventy-eight percent of Auckland children undergoing (adeno)tonsillectomy had a 25(OH) vitamin D level<75nmol/L, a level which is associated with an increased incidence of upper respiratory tract infection. Low 25(OH) vitamin D levels were related to a darker skin, increased BMI and larger assessed tonsil size. The association of larger tonsil size with lower 25(OH) vitamin D status needs further evaluation but offers a potential explanation why black and Hispanic children are more likely than white children to have (adeno)tonsillectomy for snoring or obstructive sleep apnoea.