Serum
vitamin A levels were determined in two groups of subjects living in an
endemic goiter area in Iran. The first group consisted of 242 non-goitrous subjects, and the second, contained 603 subjects with different grades of
goiter. Serum
vitamin A concentrations were correlated with
goiter, sex, and age. Serum
retinol values were not statistically different between goitrous and non-goitrous females, but goitrous male subjects especially those under 13 years of age, had lower serum
retinol values than non-goitrous male subjects. The prevalence of low
vitamin A levels was higher in goitrous boys. In both groups the prevalence of low serum
vitamin A decreased with the increase in age. The prevalence of
goiter was not statistically different between boys and girls under 18 years, but was more prevalent in women over 18 years, than men in the same age group (P less than 0.001). This difference was in accordance with serum
vitamin A status between women and men after the age of 18 (P less than 0.001). Serum
vitamin A increased with age up to 18 years, in both sexes and remained unchanged afterwards. The increase was gradual in girls under 18 years but was sharper in boys during puberty years. Although the values for serum
vitamin A in each sex covered wide overlapping ranges, but a general superiority of male serum
vitamin A levels over the females was observed.