Deficiency of<unk>  can cause tiredness, generalized weakness, muscle cramps, abnormal heart rhythms, increased irritability of the nervous system with tremors, paresthesias, palpitations, low potassium levels in the blood, hypoparathyroidism which might result in low calcium levels in the blood, chondrocalcinosis, spasticity and tetany, migraines, epileptic seizures, basal ganglia calcifications and in extreme and prolonged cases coma, intellectual disability or death.<unk>  plays an important role in carbohydrate metabolism and its deficiency may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance. People being treated on an intensive care unit (ICU) who have a low<unk>  level may have a higher risk of requiring mechanical ventilation, and death.
Magnesium deficiency
Fluorine deficiency
Boron deficiency 
Fluoride toxicity
Selenium deficiency
Thiamine deficiency
Copper deficiency
Vitamin D toxicity