Frequently Asked Questions

Questions about the Naturally-Occurring Forms of Vitamin C

Questions about Topical Vitamin C for Skin Care

Questions about Dietary Dehydroascorbic Acid

Questions about Our Products


What is L-Ascorbic Acid?

Most people recognize the name "Ascorbic Acid (AA)" and consider it synonymous with "Vitamin C." Actually, AA is one of the two naturally-occurring forms of Vitamin C. L-Dehydroascorbic Acid is the other. The L- designation refers to the biologically active stereoisomer of each of these compounds. Our products only contain the L- forms, and we frequently drop the L- from the names for simplicity.

See the Wikipedia Ascorbic acid page.


What is Dehydroascorbic Acid?

Dehydroascorbic Acid (DHAA) is the oxidized form of Vitamin C; it is one of the two naturally-occurring forms. The oxidation of Ascorbic Acid (AA) to DHAA explains the powerful anti-oxidant activity of AA. DHAA can be converted back into AA by the body, so Vitamin C is "recycled." Unfortunately though, the molecules themselves eventually break down, so the body requires a continuous supply of more Vitamin C.

See the Wikipedia Dehydroascorbic acid page.


What is Oxidized Vitamin C?

One of the most misunderstood terms by people seeking Vitamin C skincare products is the word "oxidized." It is a term used in chemistry to describe a transfer of electrons. AA becomes DHAA by being oxidized. In most solutions, AA can easily be oxidized to DHAA. Unfortunately, in those solutions, DHAA very rapidly decomposes in a complex series of additional chemical reactions. Therefore many people have come to equate the "oxidation" of AA in a product with the "decay, destruction, or decomposition" of the Vitamin C.

But it is incorrect to say that oxidized Vitamin C is the same as decomposed Vitamin C. This was a moot point before the introduction of the world's first and only product formulated to specifically stabilize DHAA...of course, we're referring to ReCverin 50/50™!


What are Vitamin C Transporters?

Every nutrient or other substance that is needed by a cell in your body must somehow get inside of that cell. Typically those substances are absorbed from the fluids that the cells are bathed in. But that doesn't mean these substances can just "soak" into the cell. The absorption of most substances is very highly controlled by means of specialized molecules or structures in the cell membrane. The absorption of Vitamin C is very highly controlled by means of special "transporters." The two naturally-occurring forms of Vitamin C use different types of transporters to be absorbed. Transporters for AA are found on some cell types, and transporters for DHAA are found on all cell types. AA is absorbed by its transporters at a relatively slow rate as compared to the absorption of DHAA by its transporters. DHAA is also absorbed to higher levels inside the cell. DHAA is converted almost instantly into AA once it gets inside the cell, so you see that both mechanisms are used to supply the cells with the same essential substance.


Is Vitamin C Unstable?

In chemical terms, to be "unstable" means that a substance changes into a different substance relatively quickly. These changes are chemical reactions, and the rate of a chemical reaction is hugely affected by conditions such as heat, light and the presence of air. Therefore stability is completely relative to conditions. Both AA and DHAA are stable for years in dry, powdered form, stored in dark bottles with all the oxygen removed, and kept cool. AA is extremely stable when dissolved in polyols such as glycerin, and DHAA is reasonably stable also. But what if you dissolve them in water? Well, AA is unstable in this condition, and DHAA is even less stable. So the AA solution will lose half of its original AA in a matter of months, or even weeks (depends on what temperature you store it at, for one thing). Most skincare products that contain Vitamin C are water-based solutions in which both forms are unstable.


Why Have I Never Even Heard of DHAA???

Among Vitamin C researchers, DHAA is very well-known and is the subject of intense and on-going investigations. It was described in a 2000 scientific review as "an important, interesting but somewhat enigmatic compound in biological systems" with "many unique properties that set it apart from ascorbic acid." (ref 1)

But DHAA is difficult and expensive to manufacture commercially, and it is extremely unstable in most solutions. A crystallized form is sold by a few specialty lab chemical suppliers for use in research, but although this crystalline substance is reasonably stable, it is an unnatural chemical form called a dimer. This dry form is difficult to dissolve, and great care must be taken when dissolving it to assure that it returns to the natural monomeric state in solution. Solutions for use as either dietary supplements or for skin care have not been available because DHAA breaks down so rapidly. Until we at ReCverin discovered how to make our patented, stabilized solutions, DHAA has essentially been unavailable to consumers. If you have never heard of DHAA, it is because, up until now, no one has been able to provide it to you in a convenient, stabilized consumer product.

(1) Deutsch JC (2000) Dehydroascorbic acid. J Chromatogr A 881: 299-307



Why Do I Need To Use Topical Vitamin C?

Almost every animal in the world makes its own Vitamin C. Human beings are very unusual--we cannot make Vitamin C in our bodies, and we will die if we don't get it in our diet. Another species that cannot make its own Vitamin C is the guinea pig.

One problem with relying on dietary intake is that this intake is sporadic. When you eat food containing Vitamin C, blood levels are maintained only for a few hours. When there is a great demand for Vitamin C, the tissue levels can be depleted. In most mammals, the liver automatically begins to manufacture large quantities of Vitamin C to replenish the blood and distribute to the needed tissues. But in humans, unless the blood levels are high and being replenished by a supply of Vitamin C in the gut, the tissues can lose much anti-oxidant protection.

Human skin is exposed to ultraviolet radiation from the sun as well as many other sources of powerful oxidizers, and can very easily become depleted of Vitamin C. Topically applied Vitamin C is absorbed into the skin and becomes an additional "pool" for the skin to use when the blood simply doesn't provide enough. Without the anti-oxidant protection of Vitamin C, the skin becomes susceptible to the damage caused by Reactive Oxygen Species.


What Are Reactive Oxygen Species? What is an Anti-Oxidant?

Reactive Oxygen Species (ROS) are chemically-reactive molecules containing oxygen. They are also called "free radicals." The basic things to know in regard to your skin is that these ROS are formed in the skin in many ways, including normal oxygen metabolism, immune-system function, and exposure to environmental oxidants and UV light; and that ROS can damage the lipids, proteins, and DNA in your skin.

An anti-oxidant is a molecule that intercepts an ROS molecule before it can damage an important lipid, protein or DNA molecule in your skin. The most important anti-oxidant in the skin is Vitamin C, being 10 times more active than all other anti-oxidants in the skin combined. The Vitamin C in your skin can become very rapidly depleted by exposure to sunlight and other environmental factors.

For more details, we recommend the Wikipedia Reactive oxygen species page.


How is Vitamin C Related to Skin Collagen?

Vitamin C has three very distinct functions related to skin collagen; protection, stimulation, and production.

  • Protection:  The skin contains a great deal of collagen, which is responsible for its strength and elasticity; degradation of collagen results in wrinkles and other signs of aging. The skin is constantly bombarded by the
    oxidizing effects of UV radiation and environmental oxidants like ozone, tobacco smoke, and pollutants. It has been shown that the Vitamin C in skin can rapidly be depleted by this exposure, and this lack of protection allows damage to the collagen by free radicals. Application of Vitamin C, in high concentrations of its absorbable forms, is necessary to assure sufficient levels in the skin.

  • Stimulation:  Studies have shown that Vitamin C can stimulate the skin to produce more collagen. It has been suggested that this is how it can improve the appearance of wrinkles. Ascorbic Acid (AA) is the natural form of Vitamin C shown to have the highest stimulating activity. A single application of 5% AA has been shown to raise skin levels fifteen times higher than the level necessary to maximize collagen stimulation. So it is clear that high concentrations in a topical product are important, but extremely concentrated solutions are not necessary for collagen stimulation.

  • Production:  Vitamin C participates in the normal production of collagen as a co-factor in a specific enzymatic step. This is its most well-known function. A complete lack of the vitamin results in improperly formed collagen, and the disease called scurvy. The symptoms of scurvy include skin signs such as bleeding into the skin, bumps or rashes, and dryness. But it takes very little Vitamin C in the diet to prevent scurvy, so it appears unlikely that anyone needs topical Vitamin C to assure that there is enough in the body to support this function.


Can Vitamin C Really "Minimize the Appearance of Fine Lines and Wrinkles?"

Yes, topical Vitamin C can minimize the appearance of fine lines and wrinkles. It's hydrating properties combined with its collagen-stimulating and collagen-protecting properties probably explain how (see above). But it concerns us that people who don't immediately see this effect often conclude that Vitamin C doesn't work for them. Making wrinkles go away is quite different from preventing them from forming in the first place. The long-term effect of topical Vitamin C on your appearance is not something that can or should be measured on the basis of whether you look 10 years younger in just a few weeks. Vitamin C provides anti-oxidant protection to ALL of the lipids, DNA, and proteins in the skin, including collagen. We believe that topical Vitamin C should be a staple of your skincare regimen for the long-term health and youthful appearance of your skin.


What Does "Anti-Aging" Mean?

Obviously, no chemical, and nothing you can buy in a bottle is going to stop you from being one day older tomorrow. Topical Vitamin C can reduce existing signs of aging such as wrinkles, and it will reduce future signs of aging by assuring that the most important anti-oxidant in the skin is not depleted. The aging effects of insufficient anti-oxidant protection are cumulative. The damage that your skin has suffered earlier in your life is revealed in the appearance of your skin today. Yet many people never start thinking about topical Vitamin C until they see the lines and wrinkles. Would you wait until you had tooth decay before you started brushing?


Does Vitamin C protect the skin from Sun Exposure?

Vitamin C is not sunscreen...it doesn't block or absorb UVA or UVB radiation. But many studies have shown that the redness of sunburn, and the formation of what are known as "sunburn cells," are both reduced by the topical use of Vitamin C. This is believed to be the result of neutralizing ROS as discussed above. Everyone should use sunscreen. Any dermatologist will tell you that a person who intentionally exposes her/his skin to intense sun is foolish. But sunbathing and tanning salons remain very popular. Since it is well known that the Vitamin C level in skin can be drastically depleted by intense sun or UV exposure, we believe that suntanners are among those who critically need topical Vitamin C.


Why are there such High Levels of DHAA in skin?

About half of the Vitamin C in normal skin is in the oxidized form known as Dehydroascorbic Acid (DHAA) (refs 1 and 2). This is highly unusual. In all other body tissues that have been measured (including adrenals, pituitary, liver, spleen, lung, kidney, testes, thyroid, heart, muscle, brain, liver, white blood cells, pancreas, eye, and plasma) Vitamin C exists almost exclusively as ascorbic acid (AA), with very little DHAA (ref 6). It is unknown why Mother Nature tries to maintain unusually high levels of DHAA in the skin.

But it is known that UV radiation from the sun can very rapidly deplete Vitamin C from the skin cells (refs 1 and 3). And it is known that DHAA is absorbed much more quickly and efficiently into skin cells (refs 4 and 5). So it is tempting to speculate that high DHAA levels are intended to most rapidly restore Vitamin C to the skin cells during periods of extreme oxidative stress.

(1) J Invest Dermatol 100:260-265 (1993)
(2) J Invest Dermatol 102:122-124 (1994)
(3) J Invest Dermatol 96:590A (1991)
(4) BiochemJ 345:665-672 (2000)
(5) J Biol Chem 270(21):12584-12592(1995)
(6) Ann NY Acad Sci 258(1) 103-118 (1975)



What Makes DHAA Superior for Topical Use?

DHAA has two chemical properties that make it superior to AA for topical use. Namely, DHAA is not ionized in solution, and it is more lipophilic than AA. These properties mean it is more gentle and can penetrate the stratum corneum more easily. (The stratum corneum is the outer layer of the skin comprised of dead, flattened skin cells. It creates a natural and desirable barrier for the protection of the living cells below, but also tends to prevent the absorption of topically applied substances, particularly ionized, water-soluble substances). In our own study, over 12 times as much DHAA was absorbed after 4 hours (see ref 1). DHAA also has three biological properties that make it superior. Namely, it is absorbed by cells much more quickly than AA, it can be absorbed by all cell types whereas AA can only be absorbed by some cell types, and thirdly it can be absorbed to higher levels in cells.


Because ReCverin 50/50™ is formulated with both AA and DHAA, it provides much more Vitamin C for the skin using lower, more gentle concentrations.


What are Chemical Derivatives of Vitamin C?

Chemical derivatives are synthetic "Vitamin C" molecules that are made by chemically linking other molecules to AA molecules. These derivatives are generally more stable than natural Vitamin C in most skincare products. Manufacturers use these derivatives to improve the shelf-life of their products. This definitely benefits the manufacturer, but the question is, "Do AA derivatives benefit you?" The next two FAQs discuss this question.


Can these derivatives be Utilized by the Skin?

Some of the commonly used derivatives are named Ascorbyl Palmitate (AP), Magnesium Ascorbyl Phosphate (MAP), Sodium Ascorbyl Phosphate (SAP), and Tetra-Isopalmitoyl Ascorbic Acid (TETRA, also called Tetrahexyldecylascorbate). Are these physiologically useful forms of Vitamin C for topical use? They certainly aren't natural; not one of these compounds exists in nature.

Chemically altering Vitamin C can have unexpected results. AP is a good example. Because AP has a lipid molecule attached, it has been shown in test tube studies (in vitro) to become embedded in the cell membrane, an unusual and unnatural location for Vitamin C. In one study, treating skin cells with Ascorbyl Palmitate "strongly promoted ultraviolet-B-induced lipid peroxidation", and the authors suggested that "...despite its antioxidant properties, ascorbic acid-6-palmitate may intensify skin damage following physiologic doses of ultraviolet radiation" (ref 1, emphasis added).

TETRA is similar to AP in that it has lipid molecules attached, but it is different in that it has no antioxidant properties whatsoever!

OK, enough of the scary stories. Lots of people have used products containing these compounds with no ill effects. But in order to be absorbed in the normal way by the skin cells, any derivative must first be changed into AA by the body. No matter what magical properties some people attribute to these compounds, in the end they are ALWAYS compared to the proven properties of natural Vitamin C, and it is ALWAYS claimed that they are converted into natural Vitamin C (AA) in the skin. There is some evidence that conversion can actually occur, but how fast and how completely this conversion can take place remains to be shown. If, for the sake of argument, we assume that these derivatives can actually be completely converted to AA in the skin, does that make them equivalent to AA? Not exactly; there is another matter to consider, and that has to do with molecular weight. Please see the next FAQ.

(1) J Invest Dermatol 119:1103-1108 (2002)



By Percent Concentration, how do derivatives compare to natural Vitamin C?

It takes a lot more of the commonly used derivatives to equal the same molar concentration of natural Vitamin C. What Percent Concentration of each derivative is comparable to 10% Ascorbic Acid?

  •   15.8%  MAP = 10% AA (MAP is Magnesium Ascorbyl Phosphate)
  •   21.6%  MAP = 10% AA (A different and commonly used form of MAP)
  •   18.3%  SAP = 10% AA (SAP is Sodium Ascorbyl Phosphate)
  •   23.6%  AP = 10% AA (AP is Ascorbyl Palmitate)
  •   64.2%  TETRA = 10% AA (TETRA is Tetrahexyldecylascorbate)


Why does it take so much more of a derivative to be equal to Ascorbic Acid? Imagine having a pound of golf balls and a pound of ping-pong balls. There are about 11 golf balls per pound, but there are many more ping-pong balls in a pound because each ball weighs less. Now, if you assume each ball is equal in value, is it better to have a pound of golf balls or a pound of ping-pong balls?

In your body, each molecule is equal in value. For example, if one molecule of AA can neutralize one free radical, then one molecule of TETRA (if it is converted to AA) can also neutralize one free radical. But each molecule of TETRA is 6.4 times heavier than each molecule of AA. In order to make percent-by-weight solutions with equal numbers of molecules, you must add 6.4 times as much TETRA.

So, if a product contains 7% TETRA, keep in mind that is about the same number of molecules as 1% AA!

Here is a link to an excellent discussion named Molecular Weight and the Mole from Kimball's Biology Pages by Professor John W. Kimball.


What about other Skin Actives and Biologicals? Why don't you put them in your products?

Our goal is to provide the purest natural Vitamin C serums in the world. Every ingredient in a skincare product, be it a product enhancer like perfume, be it an active ingredient such as Vitamin E, or be it a plant extract like Acai or Green Tea, adds another possible source of skin reaction or irritation. These additives can also affect the stability of Vitamin C. We want everyone to be able to use topical Vitamin C, with the confidence that they are using a pure, natural product.


Why is there so little DHAA in most people's diet?

Since DHAA is formed by oxidation of AA, there is a small amount in every food that has any significant amount of Vitamin C. But since DHAA is an extremely unstable chemical (far less stable than AA), very little can accumulate in foods, because it is destroyed at a more rapid rate than it is formed. However, there is one significant dietary source of DHAA. Many fresh raw vegetables, such as cabbage, squashes, pumpkins, peas, string beans, Lima beans, sweet corn, Swiss chard, carrots, parsnips, and spinach contain an enzyme called ascorbic acid oxidase that can rapidly convert AA into DHAA. AA is the predominant form of Vitamin C in these vegetables, but when the vegetables are crushed the enzyme can convert the AA into DHAA. This reaction is extremely fast--much of the AA is converted into DHAA right in your mouth while you are chewing the vegetable! Therefore in this instance, DHAA is formed at a rate much greater than it is destroyed, and the accumulated DHAA is swallowed and absorbed.

But the enzyme is rapidly destroyed by heating (ref 1), and in fact it begins to deteriorate in vegetables once they are picked. Only people who eat a lot of fresh, uncooked vegetables get very much DHAA this way. Unfortunately, most of us don't have such a natural diet.

(1) J Biol Chem 116(2):717-725 (1936)



How Stable are your products?

ReCverin C™ is probably the most stable liquid formulation of L-Ascorbic Acid in the world. Our room temperature storage studies (20 degrees C., 68 degrees F.) show neglible deterioration over a one year period, with no visual yellowing, and retention of more than 99% reducing activity. Accelerated studies (meaning storage at elevated temperatures) suggest the stability may be much longer. We feel that we are being very conservative when we say that you can easily expect ReCverin C™ to retain more than 95% of its stated activity for at least a year.

ReCverin 50/50™ is formulated with Dehydroascorbic Acid (DHAA). This form of Vitamin C is far more difficult to stabilize, and this product has a more limited shelf-life. Our storage guidelines are posted on our ReCverin 50/50™ Product Detail page. The makers of ReCverin 50/50™ have chosen to tackle the problems of instability and high cost rather than avoid them, in order to bring you the remarkable benefit of DHAA. We believe our patented formula is the best Vitamin C product in the world.