Millions of people take supplements every day, your question to be asking is are these supplements really absorbing into the body and correcting nutritional deficiencies?
Heavy synthetic metal which compose more than 90% of modern supplements are mostly un-assimilable by the body and cause liver problems much like eating powdered rocks would do. Ideally you would want to gain you nutritional needs from your daily diet, by adding things like sprouted flax seeds, algae, kelp, fungi, alfalfa, Rejuvelac and other wide spectrum vitamin and mineral sources.
Most vitamin supplements found in drug and health food stores do not contain vitamins that are truly natural, but are synthesized predominantly from petrochemicals and less frequently from plants. These are manufactured by six companies that are the sole producers of all the raw materials, which end up in the vast array of synthetic dietary supplements seen on store shelves. Also, only a small number of supplement companies, about 3%, actually manufacture their own products. The raw materials are purchased and a super assembler assembles the formulas for them.
There are three basic types of supplements: synthetic, crystalline, and whole food. These are available in numerous variations and combinations.
Synthetic vitamins are those that have been developed the laboratory. They are isolated chemical versions of vitamins. Crystalline vitamins originally had a natural food source, but have been extracted and isolated by processes that may have involved substances such as chemicals and solvents and high levels of heat. The crystalline vitamins, in the end, are much like the synthetics. "Whole food" vitamins are those that have been carefully processed and unaltered in any way that would change the molecular structure or biochemical combinations and actions of the vitamin complexes.
Many supplements claim to be "natural," but what does this really mean? To earn the right to be labeled "natural," supplements need only to originate from a natural source and/or be as little as 10% natural. Many supplements that are called natural have a food base but the primary ingredients are USP or synthetic vitamins. These would contain some co-nutrients that may assist the body in assimilating the vitamins in them.
There are companies who "grow" their vitamins in a "thick soup" of yeast and whole foods but the "nutrients" that are grown in this manner actually start out as USP (synthetic) vitamins. Nothing is going to change them from synthetic to whole and natural. Even supplements derived from natural sources such as herbs, yeast, foods such as rice bran, liver, berries, or bone can be dead and useless due to heat, pressure, or other processing techniques that destroy their enzymes. The way in which the materials are processed is extremely important in preserving the integrity of the nutrients contained therein.
Chemically, natural and synthetic vitamins are identical. The same ingredients are contained within the molecules but they are arranged in a different fashion. When a beam of polarized light passes through a natural vitamin it will always bend to the right, due to the molecular rotation of the natural substance. The letter "d" seen on some supplement labels represents dextro or "right." This indicates that the vitamin is the natural form.
As a beam of polarized light passes through a synthetic vitamin it splits into two parts, one part bending to the right and the other to the left. The synthetic supplements may be represented by the letters "dl" preceding the vitamin name. The "d" for dextro and the "l" for levo or left. This demonstrates that the molecular rotation of the synthetic is not identical to the natural form. The biological activity of synthetic vitamins can be 50% to 70% less than nutrients in natural, whole food supplements.
B vitamins are not generally referred to in conjunction with these letters but the difference in molecular structure between synthetic and a truly natural substance applies to them as well as any other nutrient.
Whole food supplements and some "natural" supplements will give foods as sources for the nutrients they contain. If a supplement is synthetic it will usually show the following as sources:
B complex – no source listed
B1 – thiamine mononitrate or thiamine hydrochloride
B2 – riboflavin
B5 – calcium D-pantothenate
B6 – pyridoxine hydrochloride
B12 – cobalamin
Folic Acid – pteroylglutamic acid
Biotin – d-Biotin
There is much controversy concerning the body’s reaction to synthetic vs. natural vitamin supplements. Many believe that the small differences between synthetic and natural are of no consequence. However, clinical evidence and several studies indicate that the body detects the difference and that natural forms of vitamins including A, B-complex, C, D, and E are more absorbable and assimilable by the body and have a more profound effect on deficiencies and disease than synthetics. This question comes to mind: Isn’t it possible that this could be true for all nutrients? Also, it has been shown that sensitive individuals who have reactions to the synthetic vitamins can take the truly natural forms with no problems.
There are some very real problems with synthetic vitamins and most supplements containing them. Not only are they synthesized, but are also isolated components completely removed from the family of micronutrients that accompany them naturally in whole foods. They are not intact with their co-factors such as enzymes, co-enzymes, vitamins, minerals, amino acids, trace elements, proteins, phytonutrients, and essential fatty acids as they would be in whole foods or properly manufactured whole food supplements. They cannot possibly have the synergistic, nutritional effect of the whole food vitamins.
Think about it! How can a dead, isolated, chemical supplement have the same action in the body as a live, whole, food concentrate? The human body was designed to recognize and utilize whole, live food not isolated chemicals. It is obvious however, that the synthetic supplements do have an effect on the body and even appear to be beneficial, at least initially.
In fact, synthetic isolates will draw the accessory nutrients needed to assimilate and metabolize in the body, from the body’s stores. It is possible for this anomaly to create deficiencies of other nutrients, or if a person is already deficient, synthetic isolates may further deplete the body and eventually cause larger and more serious imbalances.
It is not logical to expect a chemical to build the body in a nutritional sense. It is my belief that synthetic vitamins have a pharmaceutical or medical effect and whole foods, super foods, and natural whole food supplements have a nutritive effect and help to build the body’s cells nutritionally. There may be times when either may be useful, however, for the long term a truly natural supplement would be best.
There is some debate concerning whether the synthetics or the naturals work better for severe deficiencies or conditions where a quick therapeutic result is needed. There have been reports of good results and poor results with both, but according to Dr. Richard Murray synthetic vitamins fail time and time again when put to the scientific test in human feedings. Over 200 studies have proven the superior efficacy of whole foods and whole food supplements as compared to the synthetics"
http://chetday.com/bvitamins.html
Please do more research for your own interpretations, I feel this article states most of the needed topics very well and clear. The link to the original is provide to read further where multiple name brand supplements are compared.