Lactoferrin vs Vitamin C vs Elderberry: Which Children’s Immune Supplement Works?

A walk down the supplement aisle when the school term starts and you will find plenty of products promising to support your child’s immune system. Vitamin C gummies sit alongside elderberry syrups, multivitamins and increasingly, lactoferrin supplements, all competing for the attention of parents who would quite like to make it through the school term without another cold making its way around the entire family.

 

The difficult part is separating familiar ingredients from those that have evidence behind them. Vitamin C has been associated with colds for decades, elderberry has gained popularity as a natural winter remedy, while lactoferrin is less well known but has attracted growing scientific interest because of the role it naturally plays in the body’s immune defences.

 

When comparing lactoferrin vs elderberry vs vitamin C, however, the evidence in children is surprisingly different. Vitamin C is essential for normal immune function, but taking extra does not appear to prevent respiratory infections in healthy, well-nourished children. Elderberry has interesting laboratory and adult research behind it, but good-quality paediatric evidence remains limited. Lactoferrin has something particularly interesting: clinical research conducted directly in infants and children, including promising results in preschoolers who experience recurrent respiratory infections.

 

So, if you are searching for the best immune supplement for children, it is worth looking beyond the words “immune support” on the packet and asking a more useful question: what does the science show in children?

 

Lactoferrin: a natural part of the body’s first line of defence

 

Lactoferrin is an iron-binding protein found naturally throughout the human body, including in saliva, tears and mucus, with particularly high concentrations in colostrum and breast milk. It is also released by neutrophils, a type of white blood cell that acts as one of the immune system’s first responders when the body encounters invading microorganisms.

 

That gives lactoferrin a very different starting point from many ingredients marketed for immune support. It is not simply a vitamin or plant extract being introduced into the body; it is a bioactive protein already involved in our natural defence system.

 

For parents, the interesting question is how does lactoferrin help when a child encounters a bug.

How does lactoferrin support the immune system?

 

One of lactoferrin’s best-understood functions involves something surprisingly simple: iron.

 

We tend to think about iron as something our bodies need, but humans are not the only organisms that depend on it. Many bacteria also require iron to grow and reproduce, which means access to iron can become part of the battle between a pathogen and its host.

 

Lactoferrin binds very tightly to ferric iron, reducing the amount freely available to microorganisms. Scientists call this nutritional immunity, which essentially means that the body makes certain nutrients harder for invading microbes to access. Rather than attacking bacteria in the conventional sense, lactoferrin can help make their environment less favourable for growth.

 

Its potential role does not end there. Lactoferrin can interact with lipopolysaccharide, or LPS, a component of the outer membrane of certain bacteria that can provoke a strong inflammatory response when recognised by the immune system.

 

Laboratory research has also explored how lactoferrin interacts with structures called heparan sulfate proteoglycans, or HSPGs, on the surface of our own cells. Some viruses use these structures as part of the process of attaching to a cell before entering it, and lactoferrin may interfere with this initial interaction.

 

There is also an important regulatory side to the story. Lactoferrin is described as immunomodulatory, which sounds complicated but simply means that it can influence how the immune system responds rather than indiscriminately “boosting” it. Research has explored its interactions with white blood cells and antigen-presenting cells, which help the immune system identify potential threats, as well as its influence on inflammatory signalling.

 

This combination is what makes lactoferrin for children particularly interesting from a scientific perspective. It has several possible lines of defence, from controlling iron availability to interacting with microbes and influencing immune responses, rather than relying on a single pathway.

 

What does the research on lactoferrin in children show?

 

Mechanisms are fascinating, but they only take us so far. An ingredient can perform impressively in a laboratory and still fail to produce meaningful benefits when tested in people, which is why clinical research in children matters.

 

A systematic review of paediatric clinical research found that oral lactoferrin supplementation was associated with 44% lower odds of acute diarrhoea in children. Research in newborns has also investigated lactoferrin for the prevention of late-onset neonatal sepsis, with pooled findings showing lower odds of culture-proven or probable sepsis among supplemented infants.

 

For parents thinking specifically about the endless cycle of nursery and school bugs, however, respiratory research is particularly relevant.

 

A 2024 randomised controlled trial involved 50 children aged three to six who had a history of recurrent respiratory infections. Children receiving 400 mg of bovine lactoferrin each day for four months had a median of one respiratory infection during the study period, compared with two in the untreated control group.

 

The researchers also reported that active illness lasted a median of three days rather than six, while 32% of children receiving lactoferrin required corticosteroids compared with 60% of the control group. The odds of experiencing multiple respiratory infection episodes were also significantly lower in the lactoferrin group.

 

These are encouraging results, but context matters. This was a relatively small study involving preschool children who already experienced recurrent respiratory infections, so it cannot tell us that lactoferrin will halve the number of colds in every child.

 

What it does provide is something particularly valuable when comparing children’s immune supplements: clinical evidence collected directly from children, rather than benefits inferred entirely from laboratory experiments or adult studies.

 

Bovine lactoferrin has also been generally well tolerated in the paediatric clinical trials covered by the supplied evidence, with no serious supplement-associated adverse events reported in the major studies summarised.

 

Lactoferrin verdict

 

Among the three ingredients compared here, lactoferrin has the most promising direct paediatric clinical evidence for the immune outcomes examined, particularly in children prone to recurrent infections. The evidence base is still developing, but its combination of biological plausibility and human paediatric research makes it an ingredient worth watching.

 

Vitamin C for children: more is not better

 

If any nutrient has become synonymous with immunity, it is vitamin C. From orange juice when we are ill to brightly coloured “immune” gummies, the idea that more vitamin C means fewer colds is deeply ingrained.

 

There is a solid piece of science underneath that reputation. Vitamin C really is essential for normal immune function, and because humans cannot manufacture it themselves, we must obtain it through our diet.

 

Vitamin C is particularly concentrated inside immune cells such as neutrophils. When these cells attack microorganisms, they produce highly reactive molecules called reactive oxygen species, or ROS, which help destroy invading pathogens but can also damage surrounding cells if they are not carefully controlled. Vitamin C acts as an antioxidant, helping cells manage this chemically demanding environment.

 

That makes vitamin C important for immunity, but there is a crucial distinction between having enough vitamin C for the immune system to work normally and taking extra vitamin C in the hope of preventing an infection.

 

 

Does vitamin C prevent colds in children?

 

This is where vitamin C’s reputation runs ahead of the evidence. A paediatric meta-analysis examining eight randomised controlled trials involving 3,135 children found that regular oral vitamin C supplementation did not prevent upper respiratory tract infections in healthy, well-nourished children.

 

There may be a more modest benefit when it comes to how long a cold lasts. Regular supplementation has been associated with an approximately 14% reduction in cold duration in children, alongside a small reduction in symptom severity.

 

In other words, vitamin C is doing important work inside the immune system, but once a healthy child already has enough, simply adding more does not appear to create an extra protective shield against the bugs circulating at school.

 

Why can’t we just give more vitamin C?

 

The body is rather good at controlling how much vitamin C it keeps. Vitamin C is absorbed through specialised transport proteins in the intestine. As the dose rises, these transport systems become increasingly saturated, meaning the body cannot simply absorb unlimited quantities. The supplied clinical reference notes that absorption falls at very high doses and excess vitamin C is subsequently cleared through the kidneys.

 

Very high intakes can also cause diarrhoea, nausea and abdominal cramps, while excessive supplementation increases urinary oxalate, which can contribute to calcium oxalate kidney stones.

 

For a healthy child eating a varied diet containing fruit and vegetables, vitamin C should therefore be viewed as an essential nutrient that supports normal immunity, rather than a supplement that becomes progressively more protective as the dose increases.

 

Vitamin C verdict

 

Vitamin C absolutely matters for children’s health, but routine supplementation has not been shown to prevent ordinary respiratory infections in healthy, well-nourished children. If you are comparing the best supplements for children’s immune support, its reputation as a cold-prevention tool is stronger than the paediatric evidence behind that claim.

 

Elderberry for children: promising plant science, but a paediatric evidence gap

 

Elderberry, particularly Sambucus nigra, has become a familiar ingredient in winter syrups and gummies, helped by its reputation as a traditional natural remedy for coughs, colds and flu.

 

There is some interesting chemistry behind it. Elderberries contain polyphenols, a broad family of naturally occurring compounds produced by plants. Within this group are anthocyanins, the pigments responsible for the deep purple colour of elderberries, alongside compounds such as quercetin and rutin. These plant chemicals have antioxidant and other biological properties, which is why researchers have investigated whether they could influence viral infections.

 

Laboratory studies have suggested that some elderberry compounds can interact with viral glycoproteins, proteins found on the outside of viruses that help them recognise and attach to host cells. Other laboratory work has explored whether compounds found in elderberry flowers can interfere with viral attachment or influence inflammatory signalling.

 

It sounds compelling, but there is an important scientific catch: what happens to cells in a laboratory dish does not automatically tell us what will happen when a child takes a supplement.

 

Does elderberry work for children?

 

Most of the more encouraging clinical findings for elderberry come from adults. The supplied evidence includes an adult randomised controlled trial in air travellers in which elderberry extract was associated with a reduction in cold duration of around two days, alongside adult influenza studies reporting shorter symptom duration.

 

The evidence becomes much thinner when we ask the question parents need answered: does elderberry help children’s immune system?

 

The supplied clinical reference highlights the lack of rigorous paediatric clinical studies establishing elderberry’s safety or effectiveness. That means we do not currently have the same level of child-specific clinical evidence available for elderberry that we have for some of the lactoferrin research discussed above.

 

There is also an important difference between commercially prepared elderberry supplements and the elder plant itself. Raw or unripe berries, along with the stems, leaves, bark and roots, can contain cyanogenic glycosides, naturally occurring plant compounds that can release hydrogen cyanide when broken down. Improperly prepared elderberry products can therefore cause poisoning, with symptoms including nausea, vomiting, diarrhoea, dizziness and weakness.

 

This does not mean that every commercially processed elderberry supplement presents the same risk as eating raw elderberries. It does mean that “natural” should never be treated as shorthand for either “safe” or “clinically proven”, particularly when choosing supplements for children.

 

Elderberry verdict

Elderberry has interesting laboratory science and some encouraging adult research, but high-quality paediatric evidence remains limited. When choosing an immune supplement specifically for a child, that evidence gap matters.

 

Lactoferrin vs vitamin C vs elderberry: which comes out on top?

 

Putting the three ingredients side by side reveals why the phrase “immune supplement” can be misleading. They work in different ways, and the quality of evidence in children varies considerably.

 

	Lactoferrin	Vitamin C	Elderberry
Evidence in children	Promising and growing	Extensive	Limited
Respiratory infection evidence	Promising trial evidence in preschoolers with recurrent infections	Does not appear to prevent infections in healthy, well-nourished children	Not established in children
Evidence for illness duration	Promising paediatric evidence	May modestly shorten colds	Some encouraging adult evidence
What is it?	Naturally occurring iron-binding immune protein	Essential water-soluble vitamin	Plant extract containing polyphenols
How might it work?	Iron regulation, antimicrobial interactions and immune modulation	Supports normal immune cell function and antioxidant defence	Plant compounds may interact with viruses and inflammatory pathways
Paediatric safety evidence	Generally well tolerated in clinical research	Well established at appropriate intakes	Less well established
Biggest limitation	Paediatric evidence is promising but still developing	Extra supplementation does not appear to prevent ordinary colds	Lack of robust child-specific clinical research

 

There is therefore no single mechanism called “boosting immunity”. Vitamin C supplies an essential nutrient that immune cells need to function normally, elderberry provides plant compounds being investigated for antiviral and other biological effects, while lactoferrin is a protein already involved in the body’s natural defence system.

 

Of the three, lactoferrin currently offers a particularly interesting combination: a plausible biological role in innate immunity alongside promising clinical research conducted directly in children.

 

So, what is the best immune supplement for children?

 

If we restrict the question to lactoferrin vs elderberry vs vitamin C, lactoferrin currently has the most promising direct paediatric clinical evidence for the immune outcomes considered in this article.

 

That is not the same as saying lactoferrin prevents every infection. The respiratory study discussed above was relatively small and specifically involved preschool children with recurrent infections, so larger studies across broader groups of children are still needed. The evidence should be seen as promising rather than definitive.

 

Vitamin C remains an essential nutrient, but giving additional vitamin C to a healthy, well-nourished child does not appear to stop them catching ordinary respiratory infections. Elderberry has fascinating plant chemistry and some encouraging adult findings, but there is not yet enough robust paediatric research to give it the same child-specific evidence base.

 

For parents navigating the crowded children’s immune supplements UK market, that is perhaps the most useful lesson of all. Familiarity, colourful packaging and the word “natural” tell us very little about whether an ingredient has been tested in children.

 

Where do Leapfrog IMMUNE and DAILY fit in?

 

For families interested in adding lactoferrin to their routine, Leapfrog IMMUNE and Leapfrog DAILY are formulated around lactoferrin rather than relying solely on the more familiar ingredients found in many immune supplements.

 

IMMUNE combines lactoferrin with vitamin C and zinc and is suitable from age four, while DAILY provides a lower daily amount of lactoferrin alongside vitamins C, D, E and K2 and zinc for adults and children aged 12 and over. Rather than positioning supplementation as a way to stop children ever becoming ill, both formulas bring lactoferrin together with nutrients involved in normal immune function in an easy-to-use format.

 

That distinction matters because the most interesting thing about lactoferrin is not an “immune-boosting” label. It is the science behind a protein already involved in innate immune defence and the growing body of paediatric research exploring what supplementation might mean in practice.

 

 

Reference list

 

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Ali, A.S., Hasan, S.S., Kow, C.S. and Merchant, H.A. (2021). Lactoferrin reduces the risk of respiratory tract infections: A meta-analysis of randomized controlled trials. Clinical Nutrition ESPEN, 45, pp.26–32. doi:10.1016/j.clnesp.2021.08.019.

 

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