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Sayonara, Sniffles: The Evidence on Vitamin C for Immune Support and How to Boost Its Bioavailability

Sayonara, Sniffles: The Evidence on Vitamin C for Immune Support and How to Boost Its Bioavailability

With its memorable beginnings as a key player in the scurvy epidemic that killed millions of sailors between 1500 and 1800, we know that vitamin C is vital to our health—including our immune system. Although we aren’t typically prone to scurvy in our modern-day world, we still can feel the effects of inadequate vitamin C—especially when cold and flu season rolls around. Now, instead of scurvy, we’re more concerned with sneezing and sore throats.  

Research has shown that supplemental vitamin C may be able to shorten the length of cold symptoms and possibly prevent infections in higher-risk populations. However, vitamin C supplements tend to be poorly absorbed, especially in higher doses. The solution is changing vitamin C's structure or delivery system, including using liposomes or buffering it with minerals to improve absorption and utilization. 

Vitamin C’s Vital Immune Action: A Look at the Research

Vitamin C is an essential component of the immune system, as it heals wounds and infections, provides antioxidant activity, and helps to make collagen—a protein we need to grow bones, cartilage, blood vessels, skin, gums and teeth.

When it comes to research on vitamin C supplements and immunity, results are mixed. Certain populations, like those under high physical stress and obese, elderly, or metabolically dysregulated people, are thought to respond better to vitamin C supplements, while the generally healthy population may not see a difference. However, the majority of these studies utilize standard vitamin C supplements, not taking into account the poor bioavailability factor.

One meta-analysis that compiled data from nine trials found that taking 3-4 grams per day of vitamin C helped to reduce the duration of illness by half a day, shortened the time confined indoors by 10 hours, and relieved symptoms of fever and chills 8-12 hours sooner.

A review from the Cochrane Library—the best of the best when it comes to systematic reviews—found that people under high physical stress, including marathon runners, skiers, and soldiers, had a 52% reduced risk of developing a cold while taking vitamin C regularly. Plus, adults and children who supplemented with vitamin C during a cold had the duration reduced by 8% and 18%, respectively.

In addition to people under physical stress, older adults are another population more susceptible to infection due to loss of immune cell function and senescence—the irreversible growth arrest of cells. Viral infections are more common in older adults and can lead to dangerous complications, and low vitamin C levels have been observed in older adults, suggesting that this population may benefit from highly bioavailable vitamin C in supplemental form.

Boosting Bioavailability with Liposomes and Buffers

While the potential benefits of vitamin C are noteworthy, it doesn’t matter if your body can’t absorb it—which is where enhanced delivery methods like liposomes and buffers come in. 

Liposomes are nano-sized, bubble-shaped structures that are the solution to overcoming issues of poor absorption. Liposomes help nutrients or other compounds travel safely through the harsh and acidic upper digestive tract, remaining intact until they reach their target cells. 

The key to the success of liposomes comes down to their molecular structure. These microscopic bubbles consist of a double layer of phospholipids surrounding a liquid center. Phospholipids are fat-based compounds that make up our cell membranes, consisting of both a hydrophilic (water-loving) “head” that faces outward and a hydrophobic (water-hating) “tail” that is inside the bubble.

Because liposomes have a water-based center, the second layer of phospholipid heads line up to face the inside of the bubble. The double-layered bubble then safely protects the nutrient or compound inside—like vitamin C—allowing it to travel through the digestive tract and bloodstream until it meets our cells. 

The body recognizes and accepts liposomal structures because they are phospholipid-based, mimicking our own cell membranes. This means that vitamin C can be directly delivered into cells without fearing degradation or excretion in the urine before utilization. The benefits of liposomes were observed in a 2021 study, where liposomal vitamin C had over 75% improved bioavailability compared to non-liposomal vitamin C supplements.

Liposomes are nano-sized, bubble-shaped structures that are the solution to overcoming issues of poor absorption.

Another way to boost bioavailability is with buffered vitamin C, which adds minerals, like calcium or magnesium, to increase assimilation and retention. Buffered vitamin C has been found to be absorbed 400% faster than a standard vitamin C supplement and remains in the body for up to three times longer. 

Buffering also creates a more neutral pH, which is easier on the digestive system, as vitamin C is naturally acidic, and high doses can cause an upset stomach. 

Three Ways to Try Bioavailable Vitamin C

Two products at ProHealth Longevity that utilize the liposomal delivery system are Lypo-Absorb Vitamin C and Liposomal Vitamin C, both of which come in liquid form with small liposome particles.

If you’d rather pop a pill, ProHealth Longevity’s Pro-C Complex is another option that adds calcium as a buffer to increase absorption. Plus, it also contains citrus bioflavonoid compounds like rutin, rose hips, and acerola, further boosting the immune-supporting benefits. 

With these highly absorbable forms of vitamin C, your immune system will be healthy and primed all winter long—sayonara, sniffles!


Gopi S, Balakrishnan P. Evaluation and clinical comparison studies on liposomal and non-liposomal ascorbic acid (vitamin C) and their enhanced bioavailability. J Liposome Res. 2021;31(4):356-364. doi:10.1080/08982104.2020.1820521

Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;2013(1):CD000980. Published 2013 Jan 31. doi:10.1002/14651858.CD000980.pub4

Ran L, Zhao W, Wang J, et al. Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials. Biomed Res Int. 2018;2018:1837634. Published 2018 Jul 5. doi:10.1155/2018/1837634

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