Why do my muscles twitch in my calf?

Fasciculations: Fasciculations have a variety of causes, the majority of which are benign, but can also be due to disease of the motor neurons. They are encountered by virtually all healthy people, though for most, it is quite infrequent. If the neurological exam is otherwise normal and EMG testing does not indicate additional pathology, a diagnosis of benign fasciculation syndrome is usually made

Minerals and water: Your muscle twitching is most likely due to dehydration from not drinking enough water and /or you are not getting enough magnesium and potassium in your diet. You should try to drink enough water each day to keep your urine pale yellow to clear all day. You need to increase the your fruit and vegeatble intake to 5-7 sevings per day to get enough magnesium and potassium. We are what we eat.