Some people - because of media hype - take several hundred mcg of selenium a day, but Dr. Ronald Roth usually advises his own patients against higher amounts - not so much because of selenium toxicity, but because of its antagonism to chromium, magnesium, zinc and other nutritional factors. Long-term excessive intake of selenium increases the potential risk of triggering shingles, or developing trabecular osteoporosis, cystadenoma, an enlarged prostate, reduced glucose tolerance diabetes, neurological disturbances, or other negative consequences... 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...