a native hydrous magnesium silicate, sometimes with a small amount of aluminum silicate; used as a dusting powder. The inhalation of talc is associated with a wide variety of respiratory disorders.
Factors contributing to poor sleep include vitamin and mineral deficiencies. Magnesium deficiency can cause insomnia; lack of potassium can lead to difficulty staying asleep; and vitamin D deficiency has been linked to excessive daytime sleepiness.
Research has shown exercise can help to improve not only the quantity of sleep but also the quality: studies show daytime physical activity may stimulate longer periods of slow-wave sleep, the deepest and most restorative stages of sleep. A new study takes a closer look at the relationship between exercise and sleep.