Vitamin A status does not contribute to the residual goiter in schoolchildren of Isfahan, an iodine replenished area

Two thousand three hundred and thirty-one schoolchildren were selected by multi-stage random sampling. The thyroid size was estimated by inspection and palpation. The urinary iodine concentration and serum retinol (SR) were measured in 454 and 468 schoolchildren, respectively. Overall, 32.9% of 2,331 children had goiter. The median urinary iodine concentration was 195.5 mu g/l. The mean +/- standard deviation of SR in goitrous and non-goitrous children was 34.84 +/- 7.28 mu g/dl and 33.73 +/- 7.87 mu g/dl, respectively (P = 0.14). There was no child with vitamin A deficiency (SR < 20 mu g/dl) in both the goitrous and non-goitrous groups. The prevalence of subjects with low vitamin A status (SR < 30 mu g/dl) in the goitrous and non-goitrous groups was 27.7% and 33.3%, respectively (P = 0.21). In conclusion, the present study reveals that vitamin A deficiency and low vitamin A status are not among the contributing factors of goiter persistence in the studied area, and the role of other responsible factors should be investigated.