Vitamin Supplements should be designed to work with body functions and not oppose them. But, since supplements present such concentrated amounts of nutrients flooding into the body all at once, unlike foods which slowly dribble in nutrients, this aspect can upset the natural protective, digestive, and metabolic control processes. ref This point cannot be stressed enough. While the body utilizes elaborate mechanisms to limit and control nutrient absorption to prevent overloads, taxing these controls costs energy and uses up other vital nutrients and interfere with vital tissue and organ functions. This can influence and interfere with absorption avenues of other nutrients as well. Plus, overloads still occur despite these protective processes, such as with iron.
THE MENTALITY OF TOO MANY AMERICANS, "IF A LITTLE IS GOOD, MORE IS BETTER" DOES NOT HOLD FOR ALL NUTRITIONAL SUPPLEMENTS, IN FACT, NOT MANY IF ANY AT ALL.
It is not only about nutrients achieving toxic actions from higher supplemented amounts, it is also simply about how nutrients function and the ways diseases can take advantage of these functions. Diseases like some cancers hijack normal nutrient functions and use them to support rapid tumor cell growth and hinder the natural immune system defenses of the body. Nutrients like Folic acid, Vitamin B1, and Glutamine working their natural functions end up supporting many disease processes. There are balance points of nutrient amounts that needs to be respected.
Some Cancer cells develop a system to not only destroy the active form of vitamin D and speed elimination out of the body, but this system also prevents the body from activating new vitamin D. One of the normal functions of the hormone active form of vitamin D is to prevent and destroy cancer cells. Folic acid naturally participates in normal healthy cell division, a function that helps prevent cancer cells initially, but ends up speeding cancer cell growth once cancers are growing and reach a certain size. There are cancer drugs called antifolates ref that limit the action of natural folate functions in cells. This limitation hinders cancer cells hijacking folate functions for their own destructive activities. But since normal metabolism of the body needs some folate functions, this creates a dilemma. Scientists are working on a way to target antifolate actions for just cancer cells.