TY - JOUR ID - 4171 TI - Letter to Editor about "Hypothyroidism and Ramadan Fasting" JO - Journal of Nutrition,Fasting and Health JA - JNFH LA - en SN - AU - Azizi, Fereidoun AD - Research Institute for Endocrine Sciences Shahid Beheshti University of Medical Sciences, Tehran, Iran Y1 - 2015 PY - 2015 VL - 3 IS - 1 SP - 1 EP - 3 KW - Hypothyroidism KW - T4 KW - T3 KW - TSH KW - Ramadan KW - fasting DO - 10.22038/jfh.2015.4171 N2 - We have found that refeeding with a mixed diet or with carbohydrate, even though hypocaloric, reverses the changes in serum T3 and rT3 caused by fasting. This finding complements those of other studies that demonstrate the importance of dietary carbohydrate in the modulation of serum T3. Alteration in various parameters during Islamic (Ramadan) fasting is completely different from experimental fasting. From a physiological standpoint, Islamic fasting provides a unique model of intermittent daily fasting for one month. It is also distinct from regular voluntary or experimental fasting in that the faster does not drink during fasting hours. Therefore, one may assume that physiological changes occurring during Islamic fasting would differ from those observed during an experimental fast. No significant alterations in serum concentrations of T4, T3, TSH, and TSH   response to intravenous injection of TRH were found to occur in fasting males during Ramadan. In women, serum T4 and T3 concentrations may decrease in the last days of Ramadan however, the being mainly due to alterations in protein binding, as free thyroid indices remain unchanged (8, 9). A small increase in serum T4 in the last days of Ramadan has been reported by some studies, but not substantiated by others (7-10, 11). Serum T3 may decrease in pre-menarche girls without increase in serum TSH.  UR - https://jnfh.mums.ac.ir/article_4171.html L1 - https://jnfh.mums.ac.ir/article_4171_6e9ccf83552010891e584468a3fe8e28.pdf ER -