Endemic goiter in Semirom; there is no difference in vitamin A status between goitrous and nongoitrous children

Despite long-standing iodine supplementation in Iran, the prevalence of goiter remains high in some areas. This suggests other nutritional deficiencies may be considered as responsible factors for goiter persistence. In the present study we investigated the possible role of vitamin A deficiency (VAD) and low vitamin A status in the etiology of endemic goiter in Semirom, Iran.

In this cross-sectional study, 1,828 students from 108 primary schools of urban and rural areas of Semirom were selected by multistage random cluster sampling. Thyroid size was estimated in each child by inspection and palpation. Urinary iodine concentration (UIC) and serum retinol (SR) were measured.

Overall, 36.7% of schoolchildren had goiter. The median UIC was 18.5 microg/dL. The mean+/-SD of SR in goitrous and nongoitrous children was 38.84+/- 10.98 and 39.17+/-10.85 microg/dL respectively (p=0.82). There were two children with VAD (SR less than 20 microg/dL); one in the goitrous and one in the nongoitrous group. The prevalence of subjects with low vitamin A status (SR less than 30 microg/dL) in the goitrous and nongoitrous groups was 26.2 and 21.5% respectively (p=0.42).

Goiter is still a public health problem in this region. Iodine deficiency, VAD or low vitamin A status is not among the contributors of goiter persistence in schoolchildren of Semirom. The role of other micronutrient deficiencies or goitrogens should be investigated.