Category Archives: influenza

Vtamin D may help to fend off flu

Last Wednesday I posted a piece about poor vitamin D levels being linked to asthma severity.  New evidence has just emerged (1) which has found that vitamin D3 supplementation during the winter may reduce the incidence of flu (influenza A) in children, especially those suffering with asthma.

This was the first rigorously designed clinical trial to evaluate the relationship between vitamin D and diagnosed seasonal influenza (flu).  The trial was conducted in schoolchildren, aged between 6 and 15, and lasted from December 2008 until March 2009.  Children were given either 1200iu per day of vitamin D3 or an inactive placebo supplement.  Diagnosis of flu was carried out by a doctor and it was found that children receiving the vitamin D were less likely to contract flu when compared to children taking the placebo.  Specifically, the vitamin D group was 58 percent less likely to catch influenza A(1)

Interestingly children with a previous diagnosis of asthma who were taking the vitamin D had fewer asthma attacks than those taking the placebo (1).  The authors of the study hope to confirm these findings in a trial targeting children with asthma.  It has previously been found that individuals with asthma who have low levels of vitamin D in their blood are at about five times the risk for colds and flu.  A large-scale trial into the usefulness of vitamin D for improved lung function will be really interesting and important since many individuals suffer from asthma.

It is always best to check with a doctor before starting a new supplement regimen but this data adds to the volumes of research now available for the benefits of vitamin D to health.  As previously mentioned there is no current agreement over how much daily vitamin D needs to be taken in order to achieve optimal blood levels.  I would suggest most adult (age 18 and over) individuals in the UK would require a supplement of around 2000iu vitamin D daily.  Higher doses (up to 5000iu daily) may well be useful but I would not recommend such a regimen unless under the supervision of a medical doctor who can monitor blood levels regularly.  For children under the age of 18 lower doses would be necessary, perhaps in the region of about 1000iu per day as used in the study described above – however, before giving children a supplement it is always best to speak to a medical doctor. When looking for vitamin D supplements two forms are generally available.  Cholecalciferol, known as vitamin D3, and ergocalciferol or vitamin D2.  Cholecalciferol, D3, is generally taken to be the more potent, easily absorbed and preferred form of vitamin D.


(1)Urashima M et al.  2010.  Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr. 2010 Mar 10. [Epub ahead of print]

Written by Ani Kowal



Recent evidence suggests women in the UK might need a little more vitamin A

Research scientists from the University of Newcastle (1) have found that up to about 50% of women in the UK might be suffering from a lack of vitamin A.  This huge lack of this vital vitamin appears to be due to a genetic issue.  It seems that about half of the women in the UK may suffer from a genetic variation which reduces their ability to produce enough vitamin A from beta-carotene.  In the past it has been assumed that the body can convert beta-carotene into plentiful amounts of vitamin A, but this study indicates that this conventional wisdom may be misplaced.

Vitamin A is sometimes called retinol.  It is an essential nutrient, a vital vitamin that is important for a strong and healthy immune system – important to help protect against common infections, colds and flu.  Vitamin A is also crucial for healthy skin and mucous lined membranes in the nose, lungs and eyes.

In the past women were told to be careful not to consume too much vitamin A because in pregnancy too much of this vitamin seems to be associated with some birth defects.  To prevent the problem of intoxication with vitamin A pregnant women were told to avoid vitamin A rich foods and to consume beta-carotene instead.  Beta carotene is found in dark green vegetables such as Brussels sprouts, asparagus, watercress and spinach as well as orange vegetables, especially carrots, sweet potatoes and squash and orange fruits such as papaya, mangoes, cantaloupe melons, peaches, apricots.  The thinking behind this was that the body would convert as much beta-carotene as it needed into vitamin A.  This recent research (1) suggests, however, that for many women beta-carotene is not an effective substitute for vitamin A.

In a press release one of the research scientists commented (2)Vitamin A is incredibly important -particularly at this time of year when we are all trying to fight off the winter colds and flu”. “It boosts our immune system and reduces the risk of inflammation such as that associated with chest infections”.”What our research shows is that many women are simply not getting enough of this vital nutrient because their bodies are not able to convert the beta-carotene.”

Further research is certainly needed as this was only a small and preliminary study.  What the research showed (1) was that 47% of women in a volunteer group carried a genetic variation which prevented them from being able to effectively convert beta-carotene into vitamin A.  The study scientists also found that all the volunteers only consumed about one third of the recommended intake of (preformed) vitamin A.  Vitamin A is found ‘preformed’ in foods such as eggs, milk, liver, cheddar cheese, cod liver oil, salmon and mackerel.

This is a worrying statistic since many women may well be lacking enough vitamin A in their diet to reach optimal levels for body function, especially immune function.  The authors explain (2): “Worryingly, younger women are at particular risk,” “The older generations tend to eat more eggs, milk and liver which are naturally rich in vitamin A whereas the health-conscious youngsters on low-fat diets are relying heavily on the beta-carotene form of the nutrient.”

The authors comment that they need to carry out larger studies that involve both men and women.  In order to keep the immune system healthy this winter you may want to try and make sure you eat enough sources of preformed vitamin A, as well as including plenty of beta-carotene in the diet.  Taking a low dose, food-state, multi-vitamin and mineral supplement could also help by preventing any shortfalls in the diet (but a supplement should never be seen as an alternative to a healthy diet).  Until there is further evidence I don’t think it is necessary to supplement specifically with vitamin A.  Vitamin A is a fat-soluble vitamin and it is possible to take too much, so taking a low-dose multi-nutrient supplement is more advisable.  If you are pregnant always check with your doctor before taking any kind of supplement.

(1)Leung WC et al.  2009.  Two common single nucleotide polymorphisms in the gene encoding β-carotene 15,15′-monoxygenase alter β-carotene metabolism in female volunteers.   The FASEB Journal. 23:1041-1053
(2)Press release.  Newcastle University (2009, November 18). UK women at risk from vitamin A deficiency. ScienceDaily. Retrieved November 19, 2009, from
Written by Ani Kowal


The Vatican seems to be stocking up on black elderberry extract in a bid to prevent flu

Many people are understandably worried about swine flu.  A press release (1) was issued on Tuesday (11th August) providing information that the Vatican has tripled their order of black elderberry extract this year, compared to their order last year.  It seems as though the Pope may be trying a natural way to prevent influenza and boost his immune system.

This year the International Pharmacy of Vatican City has ordered 600 bottles of the black elderberry extract compared to 200 bottles last year, showing that divine intervention may work miracles, but when it comes to combating flu, even the Pope needs a helping hand (1)

Black elderberry extract (Sambucol ®) is something I have written about previously in my blog.  There is evidence suggesting that it can reduce the duration of an influenza attack by about 4 days and may  also prevent against influenza. 

Black elderberries are thought to contain a unique compound, called antivirin, which seems to coat viruses and prevents them from penetrating and infecting healthy body cells. As a result viruses, such as influenza, are unable to replicate.  This means that the body’s white blood cells can ingest the infected cells, effectively removing the virus from the body.

A press pack(2) produced about black elderberry extract details the results of a laboratory based study that took place in 2006 (3) which found black elderberry extract (Sambucol ®) effective against the H5N1 strain of bird flu (avian influenza H5N1):  “Laboratory trials were undertaken at Retroscreen Virology Ltd., a leading research institute associated with the University of London.  Sambucol ® was found to be at least 99% effective against avian influenza virus H5N1.  Sambucol ® was effective at significantly neutralizing the infectivity of the virus in cell culture.  Further studies are to be undertaken to assess the effectiveness of Sambucol ® against avian influenza (H5N1) virus infections in humans

Black elderberries also contain high levels of natural antioxidants known as flavonoids which help strengthen the immune system against viral attack; indeed the black elderberry has twice the antioxidant capacity of blueberries and significantly higher antioxidant capability than that of cranberries.

Black elderberry extracts are widely available in the UK and sold as a liquids or lozenges.  The products can be taken as a preventative or at the first signs of cold or flu-like symptoms.  A healthy diet, rich in a variety of fruit and vegetables, is obviously the most important way to keep the immune system strong, healthy and effective.  However, if you are concerned about flu and feel that your diet tends to fall short you may consider following the Popes lead and taking an elderberry extract supplement to give your immune system an extra boost.

It is very important that if you begin to experience flu-like symptoms you consult your doctor immediately.  For more information on black elderberry visit the website

(1) The Pope exorcises the flu with black elderberries.  Tuesday, 11 August 2009.  Press release distributed via Response Source, a service from Daryl Willcox Publishing, on behalf of Tiger White PR.
(2) Razei Bar.  Sambucol ®A Unique Plant Extract.  New Scientific Findings on H5N1 Bird Flu.  Press Information Kit
(3) Balasingam S et al.  2006.  Neutralizing activity of Sambucol ® against avian NIBRG-14 (H5N1) influenza virus.  Bird flu: the first pandemic of the 21st century.  A central role of antivirals.  London.
Written by Ani Kowal


‘Tis the season for influenza ……….can elderberry really help?

Unfortunately one of my very dear friends is seriously unwell, so I started writing this from the 9th floor of St Thomas’s hospital.  There are hand wash points all over the place in a bid to prevent the spread of infection.  Any hint of a sniffle and I would not be allowed to set foot onto the ward.  So, I am doing my very best to keep my immune system strong! 

In the past I have written about the prevention and treatment of colds and coughs and generally about the immune system and how to keep it strong.  It is the time of year when the cold and flu virus sis rife and people are very interested in how they can escape the infections that seem to be surrounding them.  Earlier this week I was made aware of the potential benefits of Black Elderberry extract (brand name Sambucol®) for the prevention and alleviation of the influenza virus.  I wanted to delve into the scientific research to discover if there is fact behind the hype.

Black Elderberry (sambucus nigra), a member of the honeysuckle family, is a tree-like shrub.  Traditionally various parts of the plant, including the leaves, bark, flowers and berries, have been used in medicine.  The health giving properties have been documented as far back as the 5th century.  Currently much of the interest and research has focussed on extract from the berries.  Research(1) suggests that elderberry has antiviral properties, especially against the influenza virus, and also seems to activate and boost the immune system as well as acting as an antioxidant.

The berries contain various bioactive plant compounds, known as flavonoids, as well as certain vitamins (C, A and various B vitamins), that appear to be responsible for the positive effects on the immune system and our health.

Sambucol® is a supplement that contains 38% standardised extract of black elderberry.  Research(2,3) suggests that elderberry extract appears to boost and activate the immune system in individuals who are healthy as well as those who are already suffering from a viral infection.

Two small well planned studies (randomised, placebo-controlled, double-blind studies 4,5) found that Sambucol® effectively inhibited the influenza A and B virus strains when given orally to patients in the first 48 hours of flu symptoms developing.  The earlier preliminary study (4) was very small, involving only 27 patients, but demonstrated the ability of elderberry (4 tablespoons of Sambucol® syrup per day) to reduce influenza symptoms in 20% of influenza patients within 24 hours and to reduce influenza symptoms in 75% of patients within 48 hours.  After three days of elderberry use, 90% of influenza patients experienced a total alleviation of symptoms. 

The most recent study (5) involved 60 patients aged 18-54 years who had just began (48 hours or less) to suffer from flu-like symptoms.  Participants received 15 ml of elderberry or placebo syrup four times a day for 5 days, and recorded their symptoms using a special scale.  In the participants receiving the elderberry syrup the symptoms were relieved, on average, 4 days earlier and use of rescue medication was significantly less compared those receiving placebo.  The study was small but very encouraging, the findings need to be confirmed in a larger study.

The underlying mechanism (1) for elderberry’s effectiveness in the treatment of influenza virus was discovered by an Isreili virologist, Dr Mumcuoglu.  The berry seems to be able to prevent and inhibit the replication of the influenza virus.  The active compounds within the elderberry seem to ‘coat’ or neutralise the spike-like projections that are found on the surface of several viruses, including the influenza viruses.  When these spikes are deactivated the virus is prevented from piercing the human cells, so the virus does not enter our cells and is prevented from replicating.  Unlike bacteria, a virus cannot replicate on its own, it must attack living cells in order to survive.  If the virus is prevented from entering our cells it will be unable to survive and cause us to suffer health problems.

I mentioned earlier that elderberries also possess antioxidant properties.  Antioxidants protect our cells from the damaging effects of highly reactive molecules called free radicals, which cause oxidative stress in the body.  There is mounting evidence that these destructive molecules, together with lowered antioxidant defences, play a significant role in the development and aggravation of many diseases (including cardiovascular disease and cancer to name but a few).  The body does produce its own antioxidants but also relies on vitamins, mineral and phytochemicals (bioactive plant chemical) from the diet, especially from colourful vegetables and fruits, for additional valuable supplies.

The elderberry extract, Sambucol®, is widely available in the UK as a liquid or lozenge.  The products can be taken as a preventative or at the first signs of cold or flu-like symptoms.  A healthy diet (rich in fruit and vegetables) is obviously the most important way to keep the immune system strong, healthy and effective.  However, if you are surrounded by people with colds, or worried about the ‘flu-season’ taking an elderberry extract may well give your immune system an extra boost and help you to fight off invading infections. 

(1) Sambucus nigra – monograph.  2005.  Altern Med Rev.  10(1):51-54.
(2) Barak V et al.  2001.  The effect of Sambucol® , a black elderberry-based, natural product, on the production of human cytokines:I.  Inflammatory cytokines.  Eur Cytokine Netw.  12:290-296
(3) Barak V et al.  2002.  The effect of herbal remedies on the production of human inflammatory and anti-inflammatory cytokines.  Isr Med Assoc J.  4:S919-S922
(4) Zakay-Rones Z et al.  1995.  Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra) during an outbreak of influenza in Panama.  Journal of Alternative and Complementary Medicine.  1(4):361-369.
(5) Zakay-Rones, Z et al.  2004.  Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections.  J Int Med Res.  32(2):132-140.

Written Ani Kowal