Although vitamins and minerals occur naturally in foods, a large percentage of the US population is deficient in various vitamins and minerals, due to issues related to diet, stress and disease (which both can increase vitamin demand), medication usage, gastrointestinal deficiencies in absorption and digestion, genetic variations, as well as farming practices and soil quality. Aging itself results in decreased nutrient absorption. Yet, even in relatively young patients, only a fraction of the nutrients ingested is actually absorbed into the bloodstream.
Consequently, using vitamin injections, we can raise the blood levels of nutrients much higher than that which could be achieved by diet alone, because we bypass the absorption system. Compared to taking oral supplements, a vastly larger percentage of the nutrient is actually absorbed into the system with injections. Furthermore, the higher doses can achieve benefits above and beyond those realized by reaching the RDA, which is actually determined as the level below which disease occurs, not the level at which maximum health is attained. This is the difference between the use of a vitamin to prevent disease (physiological dosage), and the use of a vitamin to treat diseases or symptoms (pharmacological dosage). Clinical experience has shown superiority of injections for this second usage (pharmacological), as illustrated in this editorial by the eminent nutritional MD, Dr. Alan Gaby, here:http://www.tidp.com/