It may seem odd for us to allow microscopic metallic pieces to roam around in our bodies. Perhaps you fear they will they will clog up your veins or arteries or cause damage to vital organs and body tissues.
Silver enters the human body through three main routes: inhaling powders and vapors containing silver, through the digestive tract (food, water, or medication), and through the skin. The adult human body contains approximately 29μg/kg of silver, and our average oral intake of silver is 20 to 80μg/day.
The absorbed fraction is carried by the bloodstream and may be deposited in various tissues throughout the body, depending on many factors. These determining factors include the size of the nanoparticles and the type of cells they are attempting to penetrate. In general, silver is stored and is accumulated intra-cellularly, apparently without any effect. This means that generally spherical silver nanoparticles can be accumulated inside our cells without disturbing the cell metabolism.
One useful tool for examining any issue is to put things into perspective, and this also holds true with the case of metals as they apply to our health. Are they naturally present in a healthy human body? Perhaps to your surprise, the answer is yes. We can examine some of these metals according to the periodic table of the elements, keeping in mind that some elements can change forms inside the body.
The information below is taken from a publication by the National Institute of General Medical Science, part o the U.S. National Institute of Health. This section concentrates its research on biological processes at a range of levels “from molecules and cells to tissues, whole organisms, and populations.”
Metals that Naturally Occur in a Healthy Human
[Ca] Calcium: Found at a level of 1.5 percent, this essential element is not just for bones and teeth. The lungs, kidneys, liver, thyroid, brain, muscles, and heart all use calcium for healthy functioning.
A healthy human body also contains traces of several metals, as listed below:
[Fe] Iron: In the blood, iron aids the transport of oxygen throughout the circulatory system. Iron is also important for proper heart function.
[Cu] Copper: Free radicals are linked to increased risks of disease. Copper helps the body collect these dangerous chemicals for safe disposal. In addition, copper is involved in the maintenance of strong limbs, good bone growth, and healthy hair.
[Mg] Magnesium: Magnesium assists in maintaining strong bones, good teeth, and proper muscle contraction/relaxation.
[Zn] Zinc: Although zinc is only present in trace amounts, its functions are quite significant. First, zinc keeps our immune responses functioning at the right levels. Second, it aids in maintaining a healthy nervous system. Zinc also helps with the regulation of hormones. A fourth function is on the gene level: Some genetic proteins require the presence of zinc in order to carry out their activities. Perhaps this is because many of our body proteins “need one or two zinc atoms to fold into the right shape.” Fifth, it has been shown that zinc is beneficial in speeding up some of the important chemical reactions in the body. Lastly, research indicates that zinc may be involved in learning and memory. Stephen Lippard, a chemist at the Massachusetts Institute of Technology (MIT), found that “zinc helps regulate communication between two types of brain cells in the hippocampus.” The hippocampus is known as the seat of memory and learning.
[Co] Cobalt: This element, the basis for Vitamin B12, aids in the formation of red blood cells.
[Mn] Manganese: Manganese is a healthy destroyer, of sorts. It is involved in the breakdown of fats, carbohydrates, and proteins, allowing food to be converted into usable energy.
Other metals present in extremely scant amounts are chromium, molybdenum, and selenium.
Last but not least, as relatively surprising as it may be, a recent Hungarian study found that there are silver-specific receptors on human tissue. Since the body is only equipped with receptors for items it requires, the logical conclusion is that topical and internal silver has a part to play in maintaining optimal human health
Colloidal Silver Conclusion 3:The presence of metals in a human body is a natural state of being. Moreover, the absence of these metals at their proper levels can lead to disease and even death. In other words, these metals are essential for the proper functioning of the human body.
Based on this conclusion, ingesting a metal is not necessarily problematic. What is important is to make sure that the absorption and elimination is acceptable to the body and that the ingested levels are not toxic. (Toxicity will be discussed in depth in the next chapter).
“This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”
 “Healthy Metals.” http://publications.nigms.nih.gov/findings/mar05/popups/lead_sb.htm
 “Metals: In Sickness and in Health.” http://www.livescience.com/18247-metals-human-body-health-nigms.html