Thyroid hormones which causes the thyroid to enlarge (the resulting medical condition is called "endemic colloid goitre"; see goitre). This has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone. Most of the thyroid hormone circulating in the blood is bound to "transport protein"s. Only a very small fraction of the circulating hormone is free (unbound) and biologically active, hence measuring concentrations of free thyroid hormones is of great diagnostic value. When thyroid hormone is bound, it is not active, so the amount of free
Nutritional neuroscience β-mono-oxygenase is affected by copper deficiency leading to increased dopamine and decreased norepinephrine levels. Both copper deficiency and toxicity can interfere with brain development and function. The neurodegenerative syndrome of copper deficiency has been recognized for some time in ruminant animals, in which it is commonly known as "swayback". The disease involves a nutritional deficiency in the trace element copper. Copper is ubiquitous and daily requirement is low making acquired copper deficiency very rare. Copper deficiency can manifest in parallel with vitamin B12 and other nutritional deficiencies. The most common cause of copper deficiency is a remote gastrointestinal surgery, such