Low Vitamin D: Rickets, osteomalacia, osteopenia, osteoporosis, bone pain, weak muscles, muscle spasms cramps, cardiovascular disease, hypocalcemia, psoriasis, higher overall mortality. Higher risk for some types of infections, cancers, or multiple sclerosis... 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...