In order to properly evaluate vitamins on health, it is first necessary to know some things about the body aging process, especially concerning cellular aging. It is fundamental to see if vitamins might have a positive impact at this basic level.
A. Cellular Age
Science is getting pretty close to controlling cellular aging as well as limiting organ age. ref But, then again, nature probably has a good reason for cellular aging processes such as cellular life-span to allow for the body to get rid of old cells so new young vibrant ones can replace. ref
Of course, there is natural aging of body parts. It is the speed of aging that is of concern here, especially to find out if vitamins have a role to play in controlling the speed of this natural process. Some people age gracefully and retain health even while growing old. Good genes obviously can play a large role, as well as actions that offer protections to prevent gene mutations. Some things that speed up mutations are known and can be avoided. And items known to increase immune processes to remain alert to repair damaged genes reap major benefits for a healthy life.
Two processes that contribute to aging include oxidation and glycation. In oxidation, free radicals are formed during normal metabolism as well as from outside toxins, like pesticides. Antioxidants (such as B vitamins & A, C, D, E, K, certain minerals, and some phytonutrients from foods) help control these reactions to limit potential damage to cell DNA. In glycation, sugars react with proteins to create unnatural protein folding patterns leading to such signs as skin wrinkles.
SKIN
Perhaps the skin is one of the best known areas where aging readily shows it effects. ref Sunshine is an external modifier of skin age. Usually this influence is negative over time. One test of skin aging is the loss of elastin and collagen fibers, or elasticity. OPC's from grape seed extract and pine bark slow down the enzymes that breakdown skin elasticity. ref Carotenoids from vegetables and fruits help protect the skin against free radicals. Vitamin C as a collagen generator is also of importance. ref Tiny amounts of copper are needed for producing elastin and collagen. ref
BONES
If bone building cells fail to develop at the same rate as bone tearing down cells, weak bones develop. Do bone building cells age faster or wear out more than bone tearing down cells? YES! ref Bone building cells are called osteoblasts. Healthy collagen is vitally involved in many ways, structurally and in stem cell differentaiation into bone building cells. This next reference reveals quite a lot of information on bone development as one ages, and what factors contribute and are targets for manipulation by treatments with drugs or more to the point, proper diet, exercise, ref and some vitamins inadequate in typical diets. ref Full version> ref
Benefit for Supplement Consumers
Scientists have discovered one general benefit for those who take a multi-vitamin supplement. Some of their body cell DNA molecules contain longer telomeres. What are telomeres? Telomeres are small elements at the ends of the DNA molecules that protect the DNA gene codes on chromosomes during replication, a cell dividing process to make an exact copy. The twisted DNA has to untwist before this replication, and then afterwards, they have to re-twist in each cell again. The telomeres give up a piece of themselves with each twist of DNA to prevent damaging the gene code material. Thus, after a certain number of divisions, the telomeres get so short they no longer are able to protect the DNA genes, and nature steps in and destroys these older DNA cells.
DEVIOUS CANCER CELLS
A rather unfortunate occurrence regarding telomeres happens in cancer cells. The cancer cells produce or activate an enzyme that enables the telomeres to not shorten with each cancer cell division. Thus, the cancer cells do not die after a programmed number of divisions like healthy cells. Cancer cell telomeres can remain active seemingly forever. Scientists are looking for a method to destroy this enzyme so cancer cells will eventually die.
The above telomere reference gives some studies for slowing down telomere shortening. EXERCISE, STRESS REDUCTION, and DIET (some supplements may help here)
How the Body Works Part two talks about vitamin impacts.