The herb thyme has recently (1) been found to suppress a specific enzyme (promotes specific biochemical reactions in the body), called Cyclooxygenase-2 (COX-2), which plays a key role in inflammation.  The researchers involved in this laboratory-based cell study found that a specific chemical found in thyme, called carvacrol, seemed primarily responsible for the inflammation suppressing activity.  Other botanical essential oils were also studied – clove, rose,e ucalyptus, fennel and bergamot – these also exhibited inflammation suppressing properties but to a lesser degree when compared to thyme, which reduced COX-2 levels by almost 75%.

Plant essential oils have been used for many years in various remedies but the way they work has not been clearly understood.  The authors of this study suggest that further understanding of the anti-inflammatory properties of various plant essential oils, or their specific components like carvacrol could be very important for future formulation of anti-inflammatory medications and remedies.

There have been a few small studies (2,3,4) using extracts of the herb thyme which have found that it may be helpful for treating the symptoms of bronchitis and coughs.  This could be due to the anti-inflammatory properties as mentioned above and also the antioxidant properties of thyme which have been demonstrated recently in cell studies (e.g.5,6).

Thyme, as well as a variety of other herbs, is now added to herbal antioxidant supplement preparations and can also be purchased as a ‘tea’ and an oil.  Further studies with the herb need to take place before any firm conclusions can be drawn and recommendations made for its use.  However, if you have a cough you may want to look out for herbal cough remedies that contain thyme or perhaps try burning a little of the oil in an oil burner, or sipping on some thyme tea to see if it brings relief to your symptoms. 

In the future I expect that more herbal preparations will be investigated and incorporated into medicines for various uses.  The antioxidant and anti-inflammatory properties of thyme and other herbs is interesting and exciting since many common health complaints are linked to inflammation and ‘oxidative stress’.

(1)Hotta M et al.  2010.  Carvacrol, a component of thyme oil, activates PPAR  and  and suppresses COX-2 expression.  Journal of Lipid Research.   51: 132-139
(2) Kemmerich B.  2007. Evaluation of efficacy and tolerability of a fixed combination of dry extracts of thyme herb and primrose root in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled multicentre clinical trial. Arzneimittelforschung.  57(9):607-15
(3) Kemmerich B et al.  2006.   Efficacy and tolerability of a fluid extract combination of thyme herb and ivy leaves and matched placebo in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled clinical trial. Arzneimittelforschung.  56(9):652-60
(4) Büechi S et al.  2005.  Open trial to assess aspects of safety and efficacy of a combined herbal cough syrup with ivy and thyme. Forsch Komplementarmed Klass Naturheilkd.  12(6):328-32.
(5) Rana P & Soni G.  2008.  Antioxidant potential of thyme extract: alleviation of N-nitrosodiethylamine-induced oxidative stress.  Hum Exp Toxicol. 27(3):215-21.
(6) Wang HF et al.  2008.  DPPH free-radical scavenging ability, total phenolic content, and chemical composition analysis of forty-five kinds of essential oils.  J Cosmet Sci.  59(6):509-22.
Written by Ani Kowal

Selenium isn’t a mineral that receives a lot of press attention, however it is an essential trace element that is incredibly vital to our health.  I first became aware of the importance of selenium for optimal health when I was studying for my MSc in Nutritional Medicine at the University of Surrey.  My professor at that time, Margaret Rayman, was (and is) a leading scientific researcher in the field of selenium.  At the time I was studying (2000-2002) there was a lot of research linking low selenium intakes to increased prostate cancer risk in men.  A very recently published paper (1) has now found that low selenium intakes seem to be tied to throat and stomach cancers too.  This is a preliminary study and further research is certainly required before any firm conclusions can be drawn.

Selenium acts as an important antioxidant in the body and this may account for part of the role it plays in cancer prevention.  As an antioxidant selenium may also be useful in preventing conditions related to inflammation such as pancreatitis, rheumatoid arthritis, systemic inflammatory response syndrome, asthma and cardiovascular disease, to name but a few.  It is also vital for a healthy immune system and plays a role in fertility in men and women.  In men it is vital for good sperm motility and in women selenium appears to be vital in very early pregnancy (2)

With regards the potential cancer protective role of selenium the antioxidant role may not be the only way that selenium acts.  Selenium also seems to act at the DNA level on specific genes in a variety of complicated ways (2)

As well as the requirement of selenium for antioxidant defence there is evidence that selenium:
* Is needed for thyroid function
* Is required by the immune system
* Has important antiviral effects
* Is needed for reproduction
* Enhances mood
* Reduces the risk of cancer
* Protects against mercury toxicity

The effect of selenium and its importance is most observable in populations where selenium status is low. The amount of selenium in the soil where food is grown determines its selenium content.  This is important here in the UK since our soils are very low in selenium.  The UK RNI (reference nutrient intake) for selenium is 75mcg/d for adult men and 60mcg/d for adult women.  However in the UK selenium intakes are estimated to be 39mcg/d which is very low and probably inadequate for most individuals (3).  Selenium intakes in the UK have fallen over the last 25 years largely due to the decrease in imports of high selenium wheat from the USA and Canada.  Plant foods are generally low in selenium in the UK/Europe where soil selenium levels are low (2).

Care is needed with supplementation since high doses of selenium can build up in the body and are toxic to health.  I would suggest not taking more that 100mcg/d.  I also do not recommend taking selenium as a single nutrient supplement since nutrients interact in complex and synergistic ways.  If you are taking a multi-vitamin and mineral supplement check to see that it contains selenium, if not then consider switching to a multi-formulation that does contain selenium.  Unfortunately dietary sources of selenium are few in the UK.  Brazil nuts (just 4-6 a day) and fish contain the highest concentrations in the diet of the UK population.  Some selenium rich flours are available to buy for cooking with

(1)Steevens J et al.  2009.  Selenium status and the risk of esophageal and gastric cancer subtypes: the Netherlands cohort study.  Accepted Manuscript, 14 December 2009.  Gastroenterology.  DOI: 10.1053/j.gastro.2009.12.004
(2) Rayman, M.P. 2000.  The importance of selenium to human health.  The Lancet 356: 233-241.
(3) BNF (British Nutrition Foundation).  2001.  Briefing Paper: Selenium and Health.

Written by Ani Kowal

Folic acid is gaining quite a lot of attention, in 2009 I mentioned it with regards the prevention of birth defects, prevention of premature births, low birth weights and also ADHD.  Recently a study (1) has also found that folic acid use pre-pregnancy and in early pregnancy is associated with a reduced risk of congenital heart defects (heart abnormality present from birth) in newborns.

The study scientists(1) looked at over 600 mothers who had delivered infants with heart defects (but without any genetic or related abnormalities).  These were compared to a ‘control’ group.  Folic acid use was associated with a reduced risk of congenital heart disease in infants  “Use of periconceptional folic acid supplements (of at least 400micrograms a day) was related to approximately 20% reduction in the prevalence of any CHD. Given the relatively high prevalence of CHD worldwide, our findings are important for public health” (1)

The authors note that the findings could be very significant since heart related birth defects can be quite common occurring in up to 2 newborns in every 100 worldwide.  When results were further broken down to look at specific heart defects it was found that women taking folic acid supplements had almost a 40% lower risk of having a child with a heart defect involving the septum, a part of the heart which separates one side of the heart from the other, compared to that of the general population (1).  This is a preliminary study but certainly deserves attention.  Further research would be necessary before any firm conclusions could be drawn

Folic acid supplements have long been recommended for all pregnant women, women planning on becoming pregnant and also women of childbearing age.  The reason for this recommendation is that folic acid is crucial for optimal foetal development very early in pregnancy, at a time when many women do not realise they are even pregnant.  At this early stage this nutrient of the B-vitamin group is known to prevent neural tube (brain and spinal cord) birth defects such as spina bifida.

If you are planning pregnancy or a woman of childbearing age who could fall pregnant it is certainly worth taking a multi-nutrient supplement which contains folic acid.  Specific supplements are available for pregnant women and those planning pregnancy and it is always a good idea to check with your doctor or midwife before starting supplementation.

Foods particularly rich in folate include leafy vegetables such as spinach, asparagus, turnip greens, lettuces, dried or fresh beans and peas, fortified cereal products, sunflower seeds, yeast extract, liver and liver products.

(1) van Beynum IM et al.  2009.  Protective effect of periconceptional folic acid supplements on the risk of congenital heart defects: a registry-based case-control study in the northern Netherlands. Eur Heart J. [Epub ahead of print]
Written by Ani kowal

Following on from my previous posts on premenstrual syndrome (PMS) I wanted to discuss the herb vitex agnus castus and how this supplement may also be useful to women suffering from PMS.  Previously I have mentioned this herb in relation to breast pain in women

The herb, vitex Agnus Castus, also known as chasteberry, grows in subtropical climates throughout the world.  Traditionally it has been used in the treatment of many ‘female ills’.  The herb itself does not contain any hormones, or hormone-like substances but it does appear to have an effect on part of the brain known as the pituitary gland which controls the production of the hormone progesterone from the ovaries.  It also appears to stop the excessive production of a hormone called prolactin which usually regulates breast-milk production but also has other, lesser-known, actions.  Prolactin is thought by some scientists to be responsible for certain PMS symptoms.  Vitex also contains the flavonoids casticin and isovitexin and it is thought that these flavonoids may help reduce the symptoms of fluid retention in PMS since flavonoids appear to facilitate repair of damage responsible for small blood vessel permeability which lead to fluid retention.

Many practitioners find that vitex agnus castus is incredibly useful in the treatment of PMS and there are many published research papers which back up their practical experiences.  Early studies (1,2,3) indicate that vitex is useful in the treatment of PMS symptoms.  One of these studies (3) published in the British Journal of Medicine concluded that “Dry extract of agnus castus fruit is an effective and well tolerated treatment for the relief of symptoms of the premenstrual syndrome”.  Symptoms that were aided with vitex agnus castus included: irritability, mood alteration, anger, headache, breast fullness and bloating.  Studies tended to run for at least 3 menstrual cycles.

A paper published this year (4) looked at the efficacy of vitex agnus castus compared to placebo treatment for PMS in over 200 women for three menstrual cycles.  The results show that the herb was safe, well tolerated and effective in the treatment of moderate to severe PMS.  Another interesting study published this year (5) found that agnus castus in combination with St.John’s Wort was effective in treating PMS-like symptoms among women starting to go through the menopause (perimenopausal women).

If you suffer from PMS on a regular monthly basis it may well be worth trying a vitex agnus castus supplement to see if it is useful for you.  The herb is commonly available as drops, tablets and capsules and most practitioners recommend that it is taken first thing in the morning upon waking up.  It may take a while before a significant benefit is seen and often it is recommended that supplements be taken for at least four menstrual cycles to determine whether or not they are proving useful to the individual woman.  The strength of supplement varies from manufacturer to manufacturer so always check the dosage instructions and adhere to those.

1.Berger D et al.  2000.  Efficacy of Vitex agnus castus L. extract Ze 440 in patients with pre-menstrual syndrome (PMS). Arch Gynecol Obstet. 264(3):150-3.
2.Loch EG et al.  2000.  Treatment of premenstrual syndrome with a phytopharmaceutical formulation containing Vitex agnus castus. J Womens Health Gend Based Med. 9(3):315-20.
3.Schellenberg R.  2001.  Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomized, placebo controlled study.  BMJ.  322:134-137. 
4. He Z et al.  2009.  Treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in China. Maturitas. 63(1):99-103
5. van Die MD et al.  2009.  Effects of a combination of Hypericum perforatum and Vitex agnus-castus on PMS-like symptoms in late-perimenopausal women: findings from a subpopulation analysis. J Altern Complement Med. 15(9):1045-8.
Written by Ani Kowal

Back in August I wrote about how diet can impact the brain and behaviour in children.  Nutrition for the brain is something I am very interested in and those of you who follow this blog will see that there is a lot of scientific evidence to show that what we eat can make a difference to mood and feelings as well as brain structure and function.

A very recent review study (1) has concluded that multi-nutrient supplementation may be associated with a small but significant increase in a measure of intelligence and academic performance in healthy schoolchildren.  The authors of the study do state however that “more research is required, however, before public health recommendations can be given” (1).

The researchers undertook the study because “Although multiple micronutrient interventions have been shown to benefit children's intellectual development, a thorough evaluation of the totality of evidence is currently lacking to direct public health policy” (1).  The aim of the research was to review the present literature on the effects of multiple-nutrient supplements on cognitive (mental/intellectual) performance in school aged children (children aged up to 18).  The researchers looked at data from trials published between 1970 and 2008 – quite a huge body of work!  As stated above, they found that multi-nutrient supplements seemed to have a small but significant positive effect on academic performance. 

The important aspect of these kinds of research studies, in my opinion, is that they show that nutrition does impact the brain, thinking, mood and therefore perhaps academic performance.  Limitations of such studies include the quality of the supplement, the quantity and also the actual diet of the child.  If you read the post from August you will see that overall diet quality is very important to the brain.  A good supply of daily vegetables, fruits, unrefined and unprocessed foods and healthy omega 3 fats as well as a protein supply with each meal is a great way to look after body and mind.  Regular exercise is also crucial for mood. 

In terms of supplements, they can never replace a healthy diet.  If you are considering supplements I would suggest a good quality multivitamin-mineral supplement, I like food-state supplements as they are made from ‘food’ and not chemicals and are easily absorbed into the body.  In addition to this I think that a daily omega 3 fatty acid supplement is definitely worth considering – these fats really are essential for the brain.  The most effective of the omega 3 fatty acids for brain function seem to be the long chain omega 3 fats EPA and DHA which are found in oily fish such as salmon, trout, mackerel and sardines.  These can be purchased as an oil or in capsule form.  Many of the oils are made easy for children to take as they are flavoured and have no fishy taste or smell.  For vegetarians and vegans flaxseed oil can be taken – this is a shorter chain omega 3 fat and not as effective, since the body has to work hard to convert it into the longer chain structure – however, it is certainly worth taking.  This kind of fat can be found in good amounts in walnuts and flaxseeds.  Vegan EPA and DHA is now being produced from algae, it is expensive but available to buy from some retailers and online.

(1)Eilander A et al.  2010.  Multiple micronutrient supplementation for improving cognitive performance in children: systematic review of randomized controlled trials.  American Journal of Clinical Nutrition.  91: 115-130
Written by Ani Kowal

Many people are currently heading back to work after an extended Christmas and New Year break.  It can be tough to get back into the swing of things after having time off and often people feel lacking in energy.  There are a few natural ways that can be useful to help provide a mood boost and prevent feelings of lethargy.

Back in September I wrote about the link between anxioxidant nutrients and symptoms such as stress, anxiety and fatigue.  It is important to keep your dietary antioxidant levels high, this will boost your immune system but may also help to combat fatigue.  The best way of providing the body with ample antioxidants is to eat a variety of colourful vegetables and fruits daily.  Get a minimum of 5 portions a day.  A good way to make sure you are always supplied is to take easy to eat fruits and vegetable stick to work with you.  Keep them at your desk and snack away guilt-free.  Blueberries, any berries in fact, are packed with antioxidants and also very tasty.  Clementines are easy to peel and readily available at the moment and most supermarkets stock carrot and celery sticks if you don’t have time to prepare your own in the morning.  You can dip these into a tomato-based salsa for an extra antioxidant hit. Any fruits and vegetables will work to boost antioxidant levels in the body – remember to eat a variety to provide an array of different antioxidants to the body.  Antioxidant supplements made from natural berries and herbs are now also available to buy but should not be viewed or used as an alternative to a healthy diet.

Magnesium is also considered a great lethargy buster.  Fatigue is thought by some in the medical field to be one of the typical early symptoms of magnesium deficiency (1).  Stress hormones can promote a reduction in tissue magnesium levels and mild magnesium deficiency may promote the feelings of fatigue.  Magnesium is an incredibly important mineral and acts as a multi-functional nutrient in the body where it is present in all cells!  It takes part in around 300 processes in the body and is vital to many bodily functions such as energy production, nerve function, muscle relaxation, bone and tooth formation, heart rhythm and aids in the production and use of insulin. 

The National Diet and Nutrition Survey (NDNS) of adults aged 19-64 (2) found that quite a shocking number of women in the UK are not achieving adequate daily magnesium intakes with 74% of women age 19-64 not reaching the RNI (reference nutrient intake) for magnesium and 85% of 19-24 year old women not beaching the RNI for this vital nutrient.  Many men (about 42%) too appear not to be reaching recommended levels.  Modern society does not eat as many whole grains, seeds, beans and nuts as in previous times and it is these sources that are rich in magnesium.  Processed foods contain little of this vital mineral.  Good dietary sources of magnesium include dried figs, almonds, hazelnuts, walnuts, cashew nuts, sunflower seeds and dark chocolate (minimum 70% cocoa solids!).  Wholegrains such as brown rice and oatmeal also contain good amounts.

Omega 3 fatty acids from oily fish such as salmon are vital for the brain and may help lift the mood.  Good dietary sources of omega 3 fatty acids include oily fish such as mackerel, salmon, sardines, trout and some nuts, especially walnuts, and flax seeds.  For people who don’t regularly eat fish considering a daily omega 3 supplement could be very helpful.  In fact I would suggest that the majority of individuals in the UK do not achieve good dietary Omega 3 intakes.  For vegetarians and vegans a flaxseed oil supplement can be useful and there are now supplements containing the longer chain omega 3 fatty acids, EPA and DHA, available which are made from algae. 

Ginseng is often taken as an energy boosting supplement.  Korean Ginseng, also known as Panax ginseng, appears to be helpful in treating and reducing stress-related fatigue (3,4,5).  A short term, one month, supplement with this herb could be worth a try.  Remember to read the label and stick to the recommended dosages.

Keeping blood sugar levels stable during the day will help prevent energy and mood slumps – a key here is to ensure you include a source of protein with each meal, this could include eggs, unprocessed meats and fish, beans, lentils or other pulses and nuts or seeds.  It is also important to avoid refined carbohydrates and minimise caffeine intake since this can disrupt hormones involved in blood sugar balance.  Eating a healthy balanced diet rich in a variety of vegetables and fruits and minimal processed and refined foods will help to keep levels of all nutrients and antioxidants high.  If you feel that you are in need of a boost or are consistently finding it hard to eat a diet rich in a variety of vegetables and fruits you could consider taking a good quality multi-vitamin and mineral supplement to cover any dietary shortfalls.  Personally I like the food-state supplements which are easily absorbed by the body and derived from natural sources.  Multi-nutrient supplements that also contain probiotics (‘good’ bacteria) are also available.  A study (6) found that such a supplement could help to reduce stress and exhaustion as well as improving the immune system.  Remember that a nutrient supplement can never be considered as an alternative to a healthy diet. 

(1)Saris N-E L et al.  2000.  Magnesium:  an update on physiological, clinical and analytical aspects.  Clinica Chimica Acta.  294:1-26, 2000.
(2)Henderson L et al.  2003.  The National Diet and Nutrition Survey: Adults aged 19-64 years.  HMSO London.
(3)Bannerjee U et al.  1982.  Antistress and antifatigue properties of panax ginseng:  comparison with piracetam.  Acta Physiol Lat Am.  32(4):277-285.
(4)Reay J L et al.  2005.  Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity.  J Psychopharmacol.  19(4):357-365, 2005.
(5)Reay J L et al.  2006.  Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks.  J Psychopharmacol.
(6)Grunenwald J et al.  2002.  Effect of a probiotic multivitamin compound on stress and exhaustion.  Adv Ther.  19:141-150
Written by Ani Kowal

Tomorrow many of us will be celebrating the New Year and perhaps reflecting on the year past and the year to come.  Resolutions (I wrote about achievable resolutions last year) are often thought out and set at this time.  When it comes to health we often look for quick fixes that are, quite honestly, unachievable – we set ourselves up for a fall.

A study due for publication next month(1), written by two psychologists from the United States, has found that individuals who make long-term plans and set-long term goals and focus on future rewards rather than instant gratification or immediate payoffs are more likely to make better, more positive decisions when it comes to their health.

The study (1) looked at many parameters for health from reducing alcohol intake to diet, regular exercise, breakfast eating and smoking.  The psychologists analysed over 450 people using three different validated questionnaires and health scales.  They were asked various questions related to their health behaviours as well as being asked to rate the extent to which they agreed or disagreed with specific statements like “I am willing to sacrifice my immediate happiness or well-being in order to achieve future outcomes”.  The results suggest that individuals who are more willing to pick later, larger rewards (i.e. future-minded individuals) are more likely to exercise more regularly, eat more healthily and drink less alcohol.

I think that the important message here is to make sure that when you set a health goal it is achievable and that you can clearly see that there will be a reward at the end.  If, for instance, you are struggling to lose weight or you have a lot of weight to shed (more than a stone for example) I think it is important not to let go of the fact that you are aiming for long-term, slow and sustainable weight loss.  Set a realistic 3 month, 6month, 9month and 12 month goal.  If it is weight loss that you are looking at then aim to lose around 2lb a week maximum and see that as a really positive step.  Focus on eating a healthy, balanced diet that is not too restrictive, allow yourself to eat what you enjoy on occasion.  If we over-restrict ourselves we are more likely to then have a total-blow out at some point which can leave us feeling dejected and like failures.

A good way to think about long term goals is to remember that making small, sustainable changes each day can add up – in a way it feels like you are doing very little but after 3 months or 6 months you get to see great results!

A few long term health ideas (for more ideas why not scan through a few of the posts on this blog):
*Exercise for 20minutes each day – that could be a power walk, an energetic dance whilst listening to your favourite radio station, a run, a fitness DVD, a swim or any other activity that gets you moving
*Eat at least 5 portions of vegetables and fruits daily – this isn’t a difficult one, with careful planning you can reach 5 and beyond a.g.  Grate an apple or chop a banana into your morning porridge, eat fruit or vegetable sticks for snacks, always have a mixed side salad with lunch and have at least 2 different types of vegetables with your evening meal
*Get enough omega 3 fatty acids.  Eat at least two portions of oily fish per week e.g. salmon, trout, mackerel or sardines.  For vegetarians it is important to get omega 3 fats into the diet, walnuts and flaxseeds are good sources.  Many people in the UK do not reach recommended levels of this vital type of fat, you may wish to consider a daily fish oil supplement to provide at least 250mg EPA and 250mg DHA a day or a flaxseed oil supplement to provide around 1000mg alpha-linolenic acid daily.  Vegan EPA/DHA supplements made from algae are becoming increasingly common too.
*Eat nuts and seeds – these are a great snack, rich in magnesium, zinc, calcium and other minerals as well as healthy fats and proteins.  Contrary to popular belief they are not fattening, 25-35g a day could help fill you up between means and keep hunger at bay.
*Include a source of protein with every meal – this helps to regulate blood sugar levels which can help reduce hunger, cravings and lethargy.  Good sources include eggs, beans/pulses/lentils, lean and unprocessed meats/fish
*Choose wholegrain, unprocessed varieties of grains, such as rice, millet, quinoa, pasta etc
*Minimise your consumption or processed and refined foods – these are often high in salt, sugar and unhealthy fats.

(1)Daugherty JR & Brase GL.  2010.  Taking time to be healthy: Predicting health behaviors with delay discounting and time perspective.  Personality and Individual Differences.  48:202-207
Written by Ani Kowal

Vitamin D really has been in the news a lot over the last two years and for good reason.  There are plenty of posts on this blog relating to the vital importance of this nutrient for optimal health and wellbeing and I think the research will continue to expand over the next few years to come.

A recently published review paper in the Journal of the American Medical Association (1) again makes a point of stressing the importance of this vitamin.  The author of the paper mentions the growing body of evidence which shows that vitamin D deficiency and insufficiency are linked to poor health outcomes for a variety of conditions – such as osteoporosis and bone fracture, muscle weakness, cancer, autoimmune disease, diabetes, schizophrenia, depression, lung dysfunction, kidney disease, and cardiovascular disease.  Although there are many hundreds of medical/scientific studies now published there is still no specific recommendation for vitamin D intakes and blood levels (1).  There is certainly a need for studies to clarify optimal vitamin D levels and to recommend safe supplementation limits.

This recent paper (1) also points out that low levels of vitamin D can be very common and mentions a study which found that in Americans aged between one and twenty-one 70% had deficient or insufficient vitamin D levels.  A truly striking figure.

So how much vitamin D is needed?
Well, unfortunately, as the paper (1) mentions, there is still no consensus on how much vitamin D is optimal for health and wellbeing.  Studies need to ascertain out how much vitamin D is needed to keep most people from becoming deficient or insufficient and also how much vitamin D can safely be taken on a daily basis.  Vitamin D is a fat soluble vitamin and is stored in the body and it is possible to take too much of it.

In the UK the majority of individuals do not get enough sunlight on their skin to generate optimal vitamin D levels in their body.  We are spending increasing amounts of time indoors, even in the summer months when there is more available sunlight.  Unfortunately vitamin D is also difficult to obtain from dietary sources, with oily fish and egg yolk being the biggest providers.  Most individuals in the UK would probably need to take a daily vitamin D supplement in order to maintain optimal levels of this vital nutrient in their blood.  The paper (1) quotes the current upper limits of vitamin D intake to be 2000IU for individuals over one year old.  However, there is also discussion which suggests that the safe upper limit could be raised to 5000IU per day for children and 10,000IU for adults (1).  (IU stands for International Units)

Interestingly the paper also mentions the fact that it may be important for us as patients to go and ask our doctors for a test to see what levels our vitamin D is in the blood.  This may be met with some resistance in the medical world but often these tests reveal that the person in question has low blood levels of vitamin D – bringing this to the attention of the medical community may actually be helpful for other individuals and to the profession as a whole (1).

Vitamin D is called the sunshine vitamin, though technically vitamin D is a hormone, as it is produced in the body when the skin is exposed to the UVB rays in sunlight (for more information on the importance of sunlight for health please visit the SUNARC centre website).  In the past it was thought that spending just 10-15 minutes in the sun everyday would supply all the vitamin D that we need – However this is now estimated not to be enough and many of us in the UK do not get enough sun on our skin to generate adequate amounts of vitamin D especially in the autumn and winter months. 

Evidence from the National Diet and Nutrition Surveys (NDNS) suggests that in the UK vitamin D deficiency is a real problem (2,3,4,5).  The problem is made worse in the older generations since, as we age our bodies find it increasingly difficult to manufacture vitamin D.

It is probable that unless you are taking a daily vitamin D supplement you may well have low levels of vitamin D in your body.  The suggested supplemental amounts vary so much, however I would not recommend supplementing more than 2000IU daily unless you are under medical supervision.

(1)Mitka M.  2009.  More evidence on low vitamin D levels fuels push to revise recommended intake. JAMA.  302(23):2527-2528
(2) Finch S et at.  1998.  National Diet and Nutrition Survey of People aged 65 Years and Over.  London: H. M. Sationery Office.
(3) Gregory L et al.  2000.  National Diet and Nutrition Survey of People aged 4-18 years. Vol 1.  Report of the Diet and Nutrition Survey.  London:  The Stationery Office
(4) Henderson L et al.  2002.  National Diet and Nutrition Survey: Adults Aged 19-64 years.  Vol 1: Types and Quantities of Foods Consumed.  London: The Stationery Office
(5) Hypponen E & Power C.  2007.  Hypovitaminosis D in British adults age 45y: nationwide cohort study of dietary and lifestyle predictors.  Am J Clin Nutr.  85:860-888.
Written by Ani Kowal