ABSTRACT
During the month of Ramadan Muslims abstain from food and drink from dawn until sunset. In order to study pituitary-thyroid function in Ramadan, serum concentrations of T4, T3, TSH and thyroglobulin and estimation of FT4I and FT3I were measured in 12 healthy women before Ramadan, and on days 1,5,10,15,20,25 and 29 of Ramadan and 10 days after fasting was terminated. There were significant decreases in serum T4 and T3 concentrations in the last week of Ramadan. However FT4I and FT3I were normal, suggesting that the decline in T4 and T3 were caused by decreased protein binding. Serum TSH and thyroglobulin were unchanged throughout the fasting period. We conclude that fasting during Ramadan does not cause alterations in the pituitary thyroid axis