Vocal folds. The vocal folds, also known commonly as vocal cords or voice reeds, are composed of twin infoldings of mucous membrane stretched horizontally, from back to front, across the larynx. They vibrate, modulating the flow of air being expelled from the lungs during phonation.
Some recent clinical studies show that vitamin D deficiency is closely related to thyroid problems. This article identifies the thyroid problems linked with vitamin D deficiency and discusses how vitamin D supplementation can help treat thyroid disorders.
Parathyroid hormone (PTH) and Vitamin D help manage calcium balance in the body. 1  PTH is made by the parathyroid glands. These are four small glands located in the neck behind the thyroid gland. 2  Vitamin D is obtained when the skin is exposed to sunlight, and from dietary sources.