Many people still assume that a higher calcium intake is key for osteoporosis prevention.  As you can see from the [...]]]>  In January  I wrote about the benefits of combined calcium and vitamin D supplements for fracture prevention.  Many adults, particularly women, are interested in eating for bone strength and prevention of osteoporosis (or brittle bones).

Many people still assume that a higher calcium intake is key for osteoporosis prevention.  As you can see from the posts linked above there are many nutrients that interact to protect our bones.  Calcium is, indeed, very important for bones however, recent evidence (1) seems to suggest that increasing calcium intakes may not help bone strength if the body is deficient in vitamin D, or body levels are insufficient.  This is a worrying concern since, as you will know from my past posts on vitamin D, most people in the UK have insufficient levels of this crucial vitamin.

This recent study (1) explored the importance of dietary calcium intake and blood serum vitamin D status with regards to bone mineral density in about 5000 women and men.  The researchers found that among men and women vitamin D status seemed to be the dominant predictor of bone mineral density relative to calcium intake.  The study highlights the importance of vitamin D and its ability to help the body utilise calcium efficiently, thus helping to explain why increasing calcium intakes alone is not always a successful way of dealing with osteoporosis prevention. 

Calcium is vital for bone mass, but nutrient interactions do need to be taken into account.  “The study supports the idea that correcting inadequate blood levels of vitamin D is more important than increasing dietary calcium intake beyond 566 mg a day among women and 626 mg a day among men for better bone mineral density” (2).  It seems that only women with the very lowest vitamin D levels seemed to benefit from higher calcium intakes.

Again, this adds to the evidence for the importance of vitamin D, to recap: most people in the UK do not get enough vitamin D and have insufficient/deficient levels in their blood.  There is no current consensus about the amount of daily vitamin D intake necessary to maintain blood levels at around 40-50 nmol/l (which is currently seen as optimal by many medical practitioners).  Most adult (age 18 and over) individuals in the UK would probably require a supplement of around 2000iu vitamin D daily.  It is always a good idea to check with a medical doctor prior to starting any supplement regimen.  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.  When looking for vitamin D supplements two forms are generally available.   Cholecalciferol, known as vitamin D3, and ergocalciferol or vitamin D2. Cholecalciferol is generally taken to be the more potent, easily absorbed and preferred form of vitamin D.

Related posts:

1. Combined vitamin D and calcium supplements for fracture prevention
2. Can calcium aid weight loss?
3. Does calcium play a role in cancer prevention?

Vitamin D and calcium are important for bone health.  With regards supplementation with these nutrients to prevent fracture the research to date has often been conflicting and inconclusive.  However, very recent evidence published in the British Medical Journal (1) has found that supplementation with both of these nutrients together is effective in fracture prevention.

Specific figures vary but it has been estimated that anywhere between 80-95% of the western female population experience premenstrual syndrome (PMS) to some level with up to about 35% seeking some kind of medical help.  Premenstrual syndrome, or PMS, is the presence of physical and/or psychological symptoms 1-2 weeks prior to the start of [...]]]>

Specific figures vary but it has been estimated that anywhere between 80-95% of the western female population experience premenstrual syndrome (PMS) to some level with up to about 35% seeking some kind of medical help.  Premenstrual syndrome, or PMS, is the presence of physical and/or psychological symptoms 1-2 weeks prior to the start of your period (menstruation).  These symptoms will typically be relieved within 2 days of the start of your period.

Over 150 different PMS symptoms have been described in various sources of literature! These can range from irritability, anxiety, mood swings and depression to fluid retention, breast tenderness, stomach bloating and headaches.  Symptoms may vary in nature and intensity between monthly cycles.  PMS is complex and varied, affecting individual women in different ways, it is definitely not predictable or easy to categorise.

There is no clear or definitive cause of PMS.  This accounts for the number and variety of symptoms that occur in women and also makes treatment difficult.  It seems that there may be many plausible factors at play including:
- Hormones
- Neurotransmitters (brain chemicals – a group of hormones formed within nerve cells)
- Prostaglandins (a type of fatty acid produced by the body that act in a similar way to hormones)
Diet and lifestyle

There is a lot that I could write about PMS and nutrition and I hope to revisit the topic in the very near future but today I wanted to look at the role that calcium supplementation may play in the treatment/prevention of this distressing condition.

Calcium has been implicated by many scientists as being important in PMS.  Women who consume more calcium from their diet seem less likely to suffer from PMS than women who consume little calcium (1) and low levels of calcium in the blood have been linked to an increased likelihood of suffering with PMS (2).  A number of well carried out clinical studies have found that calcium supplements can relieve PMS symptoms in women (3,4,5). 

Recent evidence published this year (6,7,8) has also found that calcium supplementation is very useful in the treatment of PMS.  One of these studies (8) compared the effects of hormone therapy (dydrogesterone) with a calcium and vitamin D supplement in women with severe PMS and found that the nutritional supplement was as effective as the dydrogesterone for the treatment of PMS.  This was a well designed trial which involved over 150 women.  The women were randomly assigned to take a tablet containing either 5 mg of dydrogesterone, 500 mg of calcium plus 200 mg of vitamin D, or a placebo twice daily from the 15th to the 24th day of the cycle for 2 cycles.  Treatment with dydrogesterone or calcium plus vitamin D decreased symptom severity in a similar way.  The authors conclude that “Treatment with dydrogesterone or calcium plus vitamin D had a similar effect on symptom severity in women with PMS”. 

In the UK it is currently recommended that women aim to include 700mg of calcium per day into their daily diet.  In the USA, however the recommendation is 1000mg daily.  The National Diet and Nutrition Survey (NDNS) of adults aged 19-64 (9) found that many women in the UK are not achieving adequate daily calcium intakes.  Calcium plays a role in hormone and neurotransmitter responses in the body.  This may account for some of the benefits that women with PMS gain from calcium supplementation, especially mood and pain related symptoms.  The hormone fluctuations which occur in PMS may also interfere with the way that calcium is regulated in the body causing low circulating levels which may lead to worsened PMS symptoms.

If you suffer with PMS it might be worth trying 500mg calcium daily for 3 menstrual cycles, as well as trying to boost your dietary calcium intakes, to see if you get any relief.  Good dietary sources of calcium include:nuts, especially almonds, and seeds especially sesame seeds, milk and dairy products, dried fruit (especially figs), canned fish and broccoli (The calcium found in plant foods such as pulses and wholegrain cereals does not represent a good source of available calcium – this is because these sources contain phytates which lock up the calcium and limit the amount that the body can absorb)

If you decide to take supplemental calcium it is always advisable to take magnesium as well, since the two minerals work closely together in the body and a balance is needed, magnesium deficiency has also been implicated in PMS.  For every 500mg calcium 250mg of magnesium is advised.  Vitamin D is essential for the efficient absorption of calcium into the body and also regulates blood levels of calcium.  Some studies suggest that blood vitamin D levels are lower in women with PMS and that women with the lowest vitamin D intakes are more at risk of suffering from PMS than women with the highest intakes (10).  Many supplements are available that combine these three nutrients.

For information on PMS and support please visit National association for premenstrual syndrome (NAPS) website.  NAPS is the only advocacy group in the world promoting the interest of PMS sufferers

1.  Bertone-Johnson ER et al.  2005.  Calcium and vitamin D and risk of incident premenstrual syndrome.  Arch Intern Med.  165:1246-1252. 
2.Shamberger RJ.  2003.  Calcium, magnesium and other elements in the red blood cells and hair of normals and patients with premenstrual syndrome.  Viol Trace Elem Res.  94:123-129.
3.Thys-Jacob S et al.  1989.  Calcium supplementation in premenstrual syndrome: a randomised crossover trial.  J Gen Intern Med.  4:183-189.
4.Penland, JG.  Johnson, PE.  1993.  Dietary calcium and manganese effects on menstrual cycle symptoms.  Am J Obstet Gynecol.  168:1417-1423
5.Thys-Jacobs, S et al.  1998.  Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms.  Premenstrual Syndrome Study Group.  Am J Obstet Gynecol.  179:444-452 
6. Whelan AM et al.  2009.  Herbs, Vitamins and Minerals in the Treatment of Premenstrual Syndrome: A Systematic Review.  Can J Clin Pharmacol. 16(3):e407-e429.
7. Ghanbari Z et al.  2009.  Effects of calcium supplement therapy in women with premenstrual syndrome. Taiwan J Obstet Gynecol. 48(2):124-9.
8. Khajehei M et al.  2009.  Effect of treatment with dydrogesterone or calcium plus vitamin D on the severity of premenstrual syndrome. Int J Gynaecol Obstet. 105(2):158-61.
9.Henderson L et al.  2003.  The National Diet and Nutrition Survey: Adults aged 19-64 years.  HMSO London.
10.Bertone-Johnson, ER.  Hankinson, SE.  Benedich, A.  et al.  2005.  Calcium and vitamin D and risk of incident premenstrual syndrome.  Arch Intern Med.  165:1246-1252
Written by Ani Kowal

Related posts:

1. Vitex Agnus Castus, a herb that may help women suffering with PMS
2. Magnesium as an aid to PMS symptoms
3. Combined vitamin D and calcium supplements for fracture prevention

On Monday I wrote about a potential link between low calcium intakes and overweight, especially in women.  Today I would like to write about a new piece of research (1) linking low intakes of calcium to an increased risk of cancer.

The study was the work of researchers from the National Cancer Institute in [...]]]>

On Monday I wrote about a potential link between low calcium intakes and overweight, especially in women.  Today I would like to write about a new piece of research (1) linking low intakes of calcium to an increased risk of cancer.

The study was the work of researchers from the National Cancer Institute in Bethesda, Maryland and the AARP (American Association of Retired Persons) in Washington, DC.  The researchers (1) found that higher calcium intakes were linked to a lower risk of total cancers in women; and for both men and women, it was linked to lower risk of cancers of the digestive system, and colorectal cancer in particular.

The research involved the analysis of data from 293,907 men and 198,903 women.  Intakes of dairy food and calcium from foods and supplements were assessed with a specially constructed food frequency questionnaire.  The participants were followed for an average of 7 years.  In this time 36,965 cases of cancer were identified in men and 16,605 in women (1).

In men there was no link between total calcium intake and overall cancer risk.  However in women calcium intake was linked to total cancer risk.  The risk went down as daily calcium intakes went up until reaching about 1,300mg calcium per day.  Above this level no further risk reduction was seen.  In both men and women a high calcium and dairy food intake were linked to a reduced risk of cancers of the digestive system, especially colorectal cancer.

Comparing the 20% of participants who ate the most calcium (1,530mg per day for men and 1,881 mg per day for women) with the 20% who ate the least (526mg per day in men and 494 mg per day in women) there was a significantly reduced risk of cancer of the digestive system of 16% lower for men and 23% lower for women.  Calcium intake from supplements was also linked to a lower colorectal cancer risk.

Calcium may be having a cancer preventing effect through a variety of mechanisms in the body.  In cell and laboratory studies calcium has been shown to reduce abnormal cell growth.  In the body calcium is thought to reduce damage to the mucous membrane of the large intestine.  This study certainly shows an association between higher calcium intake and a lower risk of total cancer and cancers of the digestive system, especially colorectal cancer.  However, further clinical trials are necessary before any firm conclusions can be drawn or specific recommendations made.
 

As mentioned on Monday the recommended nutrient intake for calcium in the UK for men and women aged 19-64 is 700mg per day but in the USA and other parts of the world it is higher, at around 1000mg/day.  It may be that in the UK our recommendations are revised over time in order to promote optimal health and wellbeing.  Individuals who are concerned that they are not eating enough calcium rich foods may want to consider a calcium supplement to provide 500-1000mg calcium per day.  Calcium can be found in dairy foods, broccoli, cabbage, tofu, nuts and seeds (especially almonds and sesame seeds) and tinned fish where the bones are eaten such as sardines and pilchards.

(1) Yikyung Park et al.  2009.  Dairy Food, Calcium, and Risk of Cancer in the NIH-AARP Diet and Health Study.  Arch Intern Med. 169(4):391-401.

Written by Ani Kowal

Related posts:

1. The importance of vitamin D for calcium utilisation in the body
2. Low vitamin D levels linked to colorectal cancer
3. Folate may be related to cancer prevention in women

There is no sustainable way to quickly lose weight in a healthy manner and keep it off permanently.  Eating healthily and reducing processed and refined foods will help to ensure that our bodies get all the vital nutrients that they require for optimal wellness.  Often it is not recognised that overweight or obese individuals [...]]]>

There is no sustainable way to quickly lose weight in a healthy manner and keep it off permanently.  Eating healthily and reducing processed and refined foods will help to ensure that our bodies get all the vital nutrients that they require for optimal wellness.  Often it is not recognised that overweight or obese individuals are in fact ‘starving’ in the sense that the food they may be consuming is often low in nutritive value yet high in calorific value.  In such instances the body may be encouraging overeating in an attempt to gain some essential nutrition. 

Our bodies require a vast array of vitamins, minerals, essential fats and other nutrients in order to work at their best.  Eating a diet rich in ‘natural’ foods such as vegetables, fruits, beans, nuts, seeds, unprocessed meat and fish and unprocessed wholegrain carbohydrates will help to provide the body with the vital elements necessary to maintain health.  By contrast a diet mainly based around processed foods, sugars, white bread and refined carbohydrates will be high in calories but very low in nutrients, this may cause the body to be in a state of almost constant hunger driving us to eat more in the hope of satisfying our complex nutrient needs.

A recent small study published in the British Journal of Nutrition (1) has found that taking a calcium and vitamin D supplement may help overweight and obese women to lose body fat but only if their calcium intake from food is already habitually low.  All the women in the study were asked to follow a lower-calorie diet, half the women were given a calcium plus vitamin D supplement to take in addition and half the women were given an inactive placebo supplement.  Among the women taking the calcium and vitamin D supplement who had been getting less than 600mg of calcium per day from food before the study had greater reductions in body weight and body fat, compared to women who got more calcium naturally from their usual diets.  Women who got adequate calcium from their diets prior to the study lost no more body fat over the course of the study when taking the supplement compared to women taking the placebo.

Only women with the lowest calcium intake prior to the study, less than 600 mg, seemed to get the weight and fat-loss benefits from the supplement. Supplement users lost 13 pounds, on average, versus 3 pounds in the placebo group.

The reason why the calcium and vitamin D was helpful to women who normally consumed under 600mg calcium daily is not entirely clear.  There is some evidence to suggest that the supplement was having an effect on the appetite of these women (1).  During a buffet situation it was found that the women who had been taking the supplement ate less fat than they had during a test meal done at the beginning of the research study, the same was not found in the women who were taking the placebo. 

One of the researchers said “Our hypothesis is that the brain can detect the lack of calcium and seeks to compensate by spurring food intake, which obviously works against the goals of any weight loss program.  Sufficient calcium intake seems to stifle the desire to eat more“.  In other words, the current findings seem to suggest that for overweight people with a very low calcium intake, calcium/vitamin D supplements might be very helpful for weight-loss success.  While the results from the test meals suggest that extra calcium may help calcium-deficient women curb their appetites while dieting, more research is certainly needed to confirm these preliminary results.  The research team had previously found that women who consumed diets poor in calcium had more body fat, bigger waistlines, and higher  LDL-cholesterol levels than those who consumed moderate or large amounts of calcium.

The Recommended Nutrient Intake (RNI) for adults aged 19-64 for calcium in the UK is 700mg per day, however in other countries it is recommended that women age 19-50 get 1000mg per day.  In the study (1) the women taking the supplement were receiving 1,200mg of calcium per day from the supplement.  The results of this research are interesting since overweight is becoming more common in the UK every year.  Interestingly the latest National Diet and Nutrition Survey in adults aged 19-64 in the UK (2) found that 26% of women age 19-64 had a daily calcium intake that was less than 600mg.  40% were getting less than 700mg daily and 56% less than 800mg per day.

Calcium can be found in dairy foods, broccoli, cabbage, tofu, nuts and seeds (especially almonds and sesame seeds) and tinned fish where the bones are eaten such as sardines and pilchards.  If you feel your diet may be lacking in this vital mineral you may want to consider a supplement.  Girls and women under the age of 25 may particularly wish to consider a supplement since peak bone mass is reached before this time (see my posts on osteoporosis for more information on peak bone mass and eating for bone health).  Bone strength actually peaks during our 20s. Younger people need to ‘bank’ plenty of bone by the age of 30 as bones tend not to regenerate as quickly after that.  For more information on bone health and osteoporosis please wisit the National Osteoporosis Society website. 

Readers of my blog will be aware that vitamin D has been frequently discussed and researched recently.  This vitamin works hand-in-hand with calcium.  Many of us in the UK do not receive enough of this sunlight vitamin and lack appears to be linked to all kinds of health problems.  There is also evidence that lack of vitamin D may also be linked to overweight and obesity (e.g. 3,4).  For more information on vitamin D and advice on how to achieve optimal levels please read my previous blog posts.

As I started out by saying, achieving adequate amounts of all the essential nutrients is vital for our health and probably our waistlines via an array of complex mechanisms.  Eating a nutrient rich, unprocessed diet is important for so many reasons!

(1)Major GC, Alarie FP, Doré J, Tremblay A.  2009.  Calcium plus vitamin D supplementation and fat mass loss in female very low-calcium consumers: potential link with a calcium-specific appetite control.  Br J Nutr. 101(5):659-63.
(2)National Diet and Nutrition Survey:Adults aged 19 to 64 years
(3)Richard Kremer, et al. Vitamin D Status and Its Relationship to Body Fat Final Height, and Peak Bone Mass in Young Women. J Clin Endocrinol Metab 2009;94:67–73
(4)Foss YJ. Vitamin D deficiency is the cause of common obesity. Medical Hypotheses 2009; 72(3):314-321

Written by Ani Kowal

Related posts:

1. The importance of vitamin D for calcium utilisation in the body
2. Does calcium play a role in cancer prevention?
3. Combined vitamin D and calcium supplements for fracture prevention

World Osteoporosis Day occurs on Monday October 20th and the National Osteoporosis Society (NOS) is running a UK-wide campaign ‘Love Your Bones’ which is intended to raise awareness about the importance of healthy bones.  The goal of the National Osteoporosis Society is to improve understanding of osteoporosis, what causes it and to promote the [...]]]>

World Osteoporosis Day occurs on Monday October 20th and the National Osteoporosis Society (NOS) is running a UK-wide campaign ‘Love Your Bones’ which is intended to raise awareness about the importance of healthy bones.  The goal of the National Osteoporosis Society is to improve understanding of osteoporosis, what causes it and to promote the steps people can take to keep their bones healthy and reduce their risk.

“Osteoporosis literally means ‘porous bones’. Our bones are made up of a thick outer shell and a strong inner mesh which looks like a honeycomb made up of tiny struts of bone. Osteoporosis means some of these struts become thin or break, making bones more fragile and prone to fracture. It often remains undetected until a bone is first broken, which commonly occurs in the wrists, hips and spinal bones. It is these broken bones or fractures which can lead to the pain associated with osteoporosis. Spinal fractures can also cause loss of height and curvature of the spine.”(1)

Please visit the NOS for loads more information on bone health.  They have many online and downloadable resources, including a booklet ‘Healthy Eating For Strong Bones’ and a page dedicated to the ‘Sunlight Campaign’ which highlights the fact that sunlight is one of the very best natural sources of vitamin D, a vitamin that is essential for the building of healthy bones and the prevention of osteoporosis.  The NOS point out that up to 15 % of people in the UK are estimated to have low levels of vitamin D, while 80% have levels which are considered unhealthy.  There have now been many calls for a revised vitamin D intake recommendation in the UK(2) due to extensive evidence of low levels. The NOS website provides simple tips for boosting your vitamin D levels.

Calcium and Vitamin D
A recent review paper(2) looked at the evidence surrounding the importance of calcium and vitamin D for bone health and the prevention and treatment of osteoporosis.  The paper points out that an estimated one in three women and one in twelve men aged over 55 years will suffer from osteoporosis in their lifetime.  This represents a huge cost in the UK (many millions of pounds per year).  Calcium supplements appear to be effective in reducing bone loss in women in late post menopause (after five years), particularly in those with a low daily calcium intake (less than 400 mg/d).  Supplementation with vitamin D and calcium has also been shown to reduce fracture rates in some elderly populations. Low vitamin D status is associated with an increased risk of falling and a variety of other health outcomes and is an area that requires urgent attention.

It is very important to consider bone health at an early age, this is because peak bone mass (peak bone strength) is reached before the age of 30, after this age bone gradually grows weaker.  Building up great bone strength early on in life will help reduce the risk of osteoporosis later in life.  Most studies show that calcium, supplemental or high dietary intake, is important in at a young age in order to reach a good peak bone mass (3), 600mg-1,000mg calcium daily before the age of 25 may be beneficial to reaching a good bone mass.  As mentioned above evidence regarding supplementation later in life is mixed.  However, a supplement containing vitamin D and calcium could be useful in maintaining bone mass (providing around 800mg calcium daily and 20mcg/800IU vitamin D).

Other nutrients
The role of other nutrients on bone remains to be fully defined(2), although there are promising data in the literature for links between various nutrients including: magnesium, zinc, copper, potassium, silicon, manganese, vitamin K, vitamin C, vitamin B and phytonutrients (biochemical plant compounds).  A varied, healthy diet, especially on rich in fruits and vegetables, will provide a huge array of nutrients that may positively impact bone health.  If you feel your diet is lacking you may wish to consider a high quality food-state multi-vitamin and mineral supplement.  This is NOT a substitute for good dietary habits!! 

Omega 3 fatty acids
Yes, it is the fish oils making an appearance again!  Eating a diet rich in the omega 3 fatty acids EPA and DHA, found in oily fish such as mackerel, salmon and sardines, may contribute to a reduced risk of osteoporosis by inhibiting the production of pro-inflammatory chemicals (eicosanoids) that are known to be involved in the process of bone loss.  This is a relatively new field of interest in osteoporosis.  Two recent reviews (4,5) looked at the evidence so far which does indicate a benefit, though the authors point out that further evidence is needed before firm conclusions can be drawn.  However, due to the numerous health benefits of omega 3 fatty acids (see previous blog posts) I would suggest the regular inclusion of oily fish in the diet (at least twice weekly), or taking a supplement providing around 250mg EPA and 250mg DHA a day.  For vegetarians I would suggest a daily flaxseed oil supplement to provide around 500mg alpha-linolenic acid (a shorter chain omega 3 fatty acid).

Fruits and Vegetables
A number of studies over the last decade have suggested a clear, positive link between fruit and vegetable consumption and bone health(6).  These foods provide a huge range of nutrients that are important for bone health.  In addition to the nutrients fruit and vegetables positively affect the pH balance (a measure of acid-alkali balance) in the body, by increasing the alkalinity in the body (making the body less acidic), which plays a major role in the prevention of calcium loss from bones.  Foods which are acid forming in the body include foods such as most meat and animal protein, cheddar cheese and many grain products e.g. white bread, pasta, cornflakes.  If the body is too acidic, not in pH balance, then bones can release their calcium (which increases alkalinity) into the blood to try and maintain the balance.  Obviously calcium loss is not what we want!!  Providing the body with abundant supplies of vegetables and fruits may well help to keep our bones strong as well as protecting us from many other diseases.

If you drink a lot of caffeinated tea, coffee or regularly consume fizzy drinks you may wish to reduce the amount you consume in order to protect your bones.  High intakes of these drinks can have a negative effect on bones.  The phosphoric acid they contain may cause calcium loss from bones.

Visit the National Osteoporosis Society website for more information

(1)The National Osteoporosis Society
(2) New-Lanham SA.  2008.  Importance of calcium, vitamin D and vitamin K for osteoporosis prevention and treatment.  Proc Nutr Soc.  67(2):163-76.
(3) Eastell R & Lambert H.  2002.  Strategies for skeletal health in the elderly.  Proc Nutr Soc.  61:173-180
(4)Salari P et al.  2008.  A systematic review of the impact of the impact of n-3 fatty acids in bone health and osteoporosis.  Med Sci Monit.  14:RA37-44
(5)Fernandes G et al.  2008.  Effects of n-3 fatty acids on autoimmunity and osteoporosis.  Front Biosci.  13:4015-4020
(6) New SA.  2003.  Intake of fruit and vegetables:implications for bone health.  Proc Nutr Soc.  62:889-899

Written by Ani Kowal

Related posts:

1. Fish and fish oils may be important for bone health
2. Onions and bone density, an unlikely connection?
3. The importance of vitamin D for calcium utilisation in the body