Exercise-induced spasms are among the most common causes, particularly an overuse of muscles during a strenuous workout, or under hot, humid conditions, which can affect especially those muscles that have not been well trained for the task. Muscle cramping can also occur when remaining in the same position for an extended period of time, while more severe and prolonged spasms may result from trauma such as whiplash... Full Text

Manganese may help with some symptoms of Parkinson's disease such as muscle rigidity and twitching...
Research shows that phytosterols such as beta-sitosterol may help normalize the function of natural killer cells and T-helper lymphocytes...
Iron deficiency may be suspect with some forms of ADHD. 84% of children with ADHD were found to have abnormally low levels of ferritin...
A high intake of B Vitamins can trigger heart palpitations, HBP, major complications in patients with congestive heart disease...