How do thyroid hormones support growth?

Thyroid hormones, specifically triiodothyronine and thyroxine, are essential for normal growth and development, particularly during fetal life and infancy. Their role in facilitating skeletal growth and maturation is primarily indirect, functioning through their broad stimulatory effects on cellular metabolism.123

By regulating the utilization of nutrients and oxygen consumption within the mitochondria, these hormones support the energy-intensive processes required for development. In the absence of adequate thyroid hormone, children experience significant growth retardation. Specifically, thyroid deficiency during critical early developmental stages is associated with dwarfism and intellectual disability, a severe condition known as cretinism.14

Conversely, an excess of thyroid hormone in the young can lead to the premature appearance of ossification centers and the early closure of the epiphyses, which ultimately halts further linear growth. Because of these profound impacts, routine screening for thyroid function in newborns is a critical medical practice to ensure timely treatment and healthy development.354