Fisher D A
Department of Pediatrics, Harbor-UCLA Medical Center, Torrance 90502.
J Nutr. 1989 Dec;119(12 Suppl):1865-7; discussion 1867-8. doi: 10.1093/jn/119.12_Suppl.1865.
Iodine is the rate-limiting substrate for thyroid hormone synthesis by the thyroid gland and must be available in threshold amounts to prevent goiter and hypothyroidism. Because excess iodine can inhibit thyroxine synthesis, an upper limit of iodine in infant formulas of 75 microg/100 kcal was proposed by the Food and Drug Administration in 1985. Review of recent studies of iodine physiology in infants and iodine content of milk suggests that a safe upper limit of iodine intake by normal, term infants should not exceed 100 microg/kg body wt daily. Given this limit and assuming the total intake of iodine to be derived from formula, the recommendation of 1985 still seems reasonable.
碘是甲状腺合成甲状腺激素的限速底物，必须有阈值量的碘供应，以预防甲状腺肿和甲状腺功能减退。由于过量碘会抑制甲状腺素合成，1985年美国食品药品监督管理局建议婴儿配方奶粉中碘的上限为75微克/100千卡。对近期婴儿碘生理学研究及牛奶碘含量的综述表明，正常足月婴儿碘摄入量的安全上限不应超过每日100微克/千克体重。鉴于此限制，并假设碘的总摄入量都来自配方奶粉，1985年的建议似乎仍然合理。
