For long time the importance of an adequate supply of micronutrients in nutrition for human well-being is well established. Deficiencies can implicate several serious negative effects on health status. Bruce N. Ames (University of California) points out the great importance of an adequate supply.
For many physiological processes like tissue development, detoxification or enzyme-activation  B-vitamins are essential.

For example, deficiencies of folic acid are discussed to be related with depression, cancer development and heart diseases. Further, it is well known that an increased risk to develop neural tube defects by the embryo is given by a deficit of the mother during pregnancy. Worldwide public-health campaigns recommend daily supplementation of synthetic folic acid for pregnant to reduce this risk.

A reliable and complete database about Vitamins is given by MedlinePlus.

Some micronutrients like zinc or selenium are toxic in large doses but small quantities are essential in all known forms of life. Selenium's main role in organisms is to act as antioxidant. Dietary selenium comes from nuts, cereals, meat, fish and eggs. Deficiencies can occur in patients with severely compromised intestinal function given by mal-absorption.
Zinc plays a significant role in a relatively small but essential part of proteins in human body. Moreover a small part of tissues like prostate or intestine, contain cells that secrete zinc ions. The roles of these secreted zinc signals are now being actively studied. Signs of zinc deficiency include hair loss, skin lesions, diarrhea and wasting of body tissues. On the other side excessive absorption of zinc can suppress copper and iron absorption.



An adequate supply is the golden standard
The list of micronutrients and its functions is much longer. The main aim of this short article is to purpose in the current article- and media-jungle of nowadays some reliable links and literature about this, some times controversial discussed theme. So, for further information about intake and significance we recommend to consult these websites:


Nutrition.gov - Smart nutrition starts here
Die deutsche Gesellschaft für Ernährung (German)
Die österreichische Gesellschaft für Ernährung (German)
Ames BN. DNA damage from micronutrient deficiencies is likely to be a major cause of cancer. Mutation Research 2001; 475(1-2):7-20.
Eichholzer M. et al. Folic acid: a public-health challenge. The Lancet 2006; 367: 1352-61