"Natural heme iron has been used largely in Scandinavia for more than 30 years. It has no known side-eects and tolerance is at placebo-level in clinical studies. No serious side eects or poisonings have ever been reported. Natural heme iron is the only alternative to syntethic iron in supplements as there are only two kinds of oral iron the human body can utilize. Heme iron is the most ecient way to orally supplement iron depletion."