This paper discusses physiochemical similarities between synthetic and natural vitamins, established clinical benefits of natural vitamins, and how this label can impact medical research and practice. It concludes that current lessons of science and history corroborate the claim that natural vitamins are much nutritionally better than synthetic ones. Synthetic vitamins include the majority of the over the counter and prescription vitamin forms on the market today. The claims for these products are often based on false claims regarding their ability to elicit greater biological responses than do chemically synthesized forms of vitamins.

The claims of greater therapeutic benefits advanced by companies producing synthetic vitamin supplements are based on inadequate testing to demonstrate their effectiveness. Few studies have examined the effect of synthetic vitamin supplements on vital biochemical processes such as blood clotting, growth, antioxidant status or DNA repair. Even fewer studies have compared the therapeutic effects of natural vitamins with those of synthetic products. Synthetic vitamins typically do not compare favorably with natural vitamin supplements, when taken in their recommended daily doses.

Most of natural vitamins and minerals are lipid-soluble in nature, requiring the mediation of co-factors in order to be absorbed and utilized by cells and organs. Co-factors play a key role in ensuring that nutrients are adequately absorbed and used by the body. Common co-factors found in natural sources of vitamins and minerals are fatty acids, amino acids, phytosterols, co-factors of cellular metabolism, liposomes, and enzymes. Some of these substances are more commonly found in plant foods and beverages than in pharmaceutical preparations. Some co-factors, such as the fatty acid lecithin, are naturally found in dairy products, whereas others, like the antioxidant polyphenols, are produced by plants and are only available in diet supplements.

The molecular structure of natural vitamins is different from that of synthetic vitamins. Molecules of different sizes join to form different shapes within the vitamin molecule. When vitamin molecules are formed in the lab, several additional chemical structures called cross-links occur. These additional chemical structures provide a bridge between the atomic base of the vitamin molecule and the lipid layer that coats it. The thickness of this lipid layer has a profound effect on the effectiveness of the vitamin, because the greater the thickness of the lipid, the more readily the vitamin is absorbed and used by the body.

One major difference between natural vitamins and their synthetic counterparts is that natural vitamins have a single crystalline center, while synthetic vitamins have multiple conformations (amines, peptides, etc.). In addition, natural vitamins have a much higher rate of stability than their synthetic counterparts. All vitamin C supplements that are currently on the market are synthesized, but only natural vitamin C is considered to be a stable vitamin because of its single crystalline structure. In comparison, the synthetic form of vitamin C is unstable because of its various cross-links and is much more prone to being destroyed by stomach acid. It is not uncommon for patients to experience mild gastrointestinal symptoms when taking vitamin C in the synthetic form, which is due to the instability of the vitamin.

Synthetic vitamins also have several side effects. Like natural vitamins, they can be manufactured in higher concentrations than allowed under the Food Quality Act (FQA). They also often contain added fragrances or colorings that may be inappropriate for use in topical applications.

Another key difference between natural vitamin supplements and their synthetic counterparts is that while synthetic vitamins tend to lose their potency over time, natural vitamins retain their potency indefinitely. Because of this, natural vitamin supplements are usually more affordable than their synthetic counterparts. They also provide the same health benefits, although their efficacy may vary depending on the quality of the vitamin supplement and the potency of the compounds included. However, as long as the supplement contains a sufficient amount of the right nutrients (such as A, C, E, and B complexes), it will work just as well as a synthetic vitamin.

The majority of natural vitamins tend to be water-soluble, which means that they are not absorbed through the lining of the intestines. In contrast, synthetic supplements are easily absorbed through the intestinal walls, although they tend to lose their effectiveness over time. Water-soluble vitamins and minerals occur naturally in many foods, such as fruits, vegetables, wheat products, dairy products, etc., so it is extremely difficult to come across a deficiency of any one of these vitamins or minerals. Natural vitamin c supplements are available in tablet and powder forms, but the powder form is by far the most convenient for consumption. This is because the powder can be easily mixed into any juice, smoothie or other drink, whereas it is impossible to add a tablet to tea.