How Vitamin C is Taken

Food vs Tablet vs Liposomal

Food, tablet, and liposomal forms of vitamin C each have their advantages and we believe that it is optimal to combine the different forms.

Vitamin C from Food

Vitamin C in food is chemically identical to vitamin C in supplements. The difference between consuming vitamin C in food and consuming vitamin C in a supplement is the other substances that the food and supplement contain.

An excellent review of the literature on the Bioavailability of Vitamin C from Food versus Supplements has been published.

Studies have overwhelmingly shown that vitamin C from food and vitamin C from supplements are equally bioavailable.

As an example, no differences in bioavailability were observed in the plasma, urine, semen, leukocytes, or muscle tissue following six weeks of supplementation versus six weeks of eating kiwifruit for the same amounts of vitamin C. Meanwhile, a pharmacokinetic study showed comparable changes in plasma vitamin C and the excretion of vitamin C over an 8-hour period following the oral consumption of supplements and kiwifruit for the same amounts of vitamin C.

It has been suggested that flavonoids and vitamin E present in food can act as oxidants, thus sparing vitamin C from playing the role of oxidant and allowing the further use of vitamin C in the body. Animal studies found vitamin C to be more bioavailable from food than from supplements and more bioavailable when in the presence of isolated bioflavonoids. However, these results have not translated to people, for which no difference in bioavailability has been observed.

An advantage of consuming vitamin C in food is that the vitamin C will assist in the absorption of other nutrients present, such as iron. Furthermore, food obviously contains many nutrients other than vitamin C. Therefore, supplements do not replace a balanced diet.

However, a balanced diet does not produce the quantity of a vitamin required for therapeutic use. It takes 10 kiwifruit or 20 oranges or 20 lemons to reach the typical amount of vitamin C present in a single vitamin-C tablet (i.e., 1000 mg). Food is therefore limited as a medicinal source of vitamin C.

Vitamin C Tablets, Powders, and Gummies

Tablets and powders are effective and inexpensive.

Tablets and powders can be taken to get up to a few grams (a few thousand micrograms) of vitamin C per day as a maintenance dose.

As the percentage of vitamin C absorbed by the body decreases with the size of the oral dose above a dose of about 200 mg, it is advantageous to spread out the oral intake of vitamin C tablets and powders over the course of the day.

The blood plasma level of vitamin C peaks 2 to 3 hours after the vitamin C is taken.

Chew-able tablets and gummies typically contain glucose and other sugars. Sugars feed bacteria and viruses, and taking a chew-able tablet or gummy is thus counter-productive to fighting illness. It is better to take a non-chewable tablet. A child too young to swallow a tablet can take liposomal vitamin C.

Liposomal Vitamin C

Vitamin C encapsulated in liposomes has come onto the market in the past decade.

Liposomes are spherical shells of phospholipids that have long been manufactured in the medicine industry to deliver drugs to cells.

There is some evidence that liposomes increase the bioavailability of the vitamin C molecules that they contain. As an example, in one study, a 4-g (i.e., 4000-mg) dose of liposomal vitamin C resulted in a peak blood plasma level of vitamin C (three hours later) of 3.2 mg/dL whereas the same dose of a regular vitamin C supplement resulted in a peak blood plasma level of 2.4 mg/dL.

However, the consumer may not consider this difference to be appreciable given that liposomal vitamin C is typically 10 times the price of tablet/powder vitamin C.

Here at Cellular Medicines, we consider that the main advantage of liposomal vitamin C is that it allows a greater dose of vitamin C to be taken. A daily maintenance dose of 10 grams (10,000 micrograms) of vitamin C is easily tolerated by most people as the vitamin C is encased in lipids (fats) and digested via the lymph system.

The liposomes themselves are constructed from phospholipids, which are typically sourced from sunflower, egg, or soy lecithin. Phospholipids themselves have nutritional benefit and are sold as supplements in their own right.

Most liposomal products are foul tasting. A major accomplishment in producing liposomal products here at Cellular Medicines was creating an enjoyable taste.

Absorption of Vitamin C in the Body

Vitamin C is actively absorbed into the body via two sodium-dependent vitamin C transporters, SVCT1 and SVCT2. These transporters co-transport sodium and vitamin C across cell membranes. Their ability to accumulate vitamin C in cells is determined by the sodium gradient across the cell membrane. The sodium gradient is maintained by the activity of Na+/K+-ATPase. SVCT1 is expressed in epithelial tissues and is primarily responsible for the intestinal uptake and renal reabsorption of vitamin C while SVCT2 is expressed in specialized and metabolically active tissues that require much vitamin C for enzymatic reactions and/or protection from oxidative stress.

Furthermore, the oxidized form of vitamin C, dehydroascorbic acid, is absorbed via hexose transporters (GLUTs 1, 2, 3, and 8), in competition with the absorption of glucose, before being rapidly reconverted to the reduced form of vitamin C, ascorbate.

Vitamin C accumulates in cells and tissues. The highest concentrations are found in leukocytes, the eyes, adrenal glands, the pituitary gland, and the brain.