On the 22 October I mentioned the potential use of Vitamin D supplements for helping individuals suffering from the mood disorder SAD (seasonal affective disorder).  This year a number of papers have been published (1,2,3,4) which suggest that vitamin D could potentially be useful for the treatment of other mood disturbances and depressive episodes.

In 2007 a review paper was published (5) which suggested that vitamin D deficiency may play a role in depression and other mood and mental health disturbances, especially in the elderly where low vitamin D levels are commonly found.  The paper highlighted a number of trials that which showed that vitamin D supplementation appeared to be useful in the treatment of depression but expressed a need for further studies.

Vitamin D seems to be a hot topic this year and I have written about it a number of times in my blog posts.  Low vitamin D levels seem to be linked to cancer, heart disease, SAD, chronic fatigue syndrome, migraine headaches and various other diseases, not only bone conditions such as osteoporosis and osteoarthritis.  It is becoming glaringly obvious that this ‘sunshine vitamin’ is more important than we once thought. 

Two studies this year have linked low vitamin D status, as measured by low circulating blood levels of vitamin D, with depressive symptoms.  One study (1) was carried out in overweight and obese individuals and the other (3) in older adults (aged 65 – 95 years).  Both studies found that there was an association between depression status and severity with decreased serum (blood) vitamin D levels.  In the study with overweight/obese participants high-dose vitamin D supplementation led to significant improvements in depressive symptoms, compared to placebo, during the study.  The studies so not prove a causal relationship between low vitamin D and depression but they do add to the mounting evidence which suggests a very real link.  Further, larger studies will be needed to verify the information and investigate this exciting association further.

It is not currently known why vitamin D may be useful in treating mood disorders or why low levels may have a part to play in causing mood problems.  It may be that vitamin D has an effect on hormones linked to mood.  Studies are bound to unravel the mystery over the next few years!

A recent analysis(6) found that there is a global widespread insufficiency of vitamin D and there is evidence from the National Diet and Nutrition Surveys (NDNS) which suggests that in the UK deficiency of this vital nutrient is a real problem (7,8,9,10).  The problem is made worse in the older generations, as we age our bodies find it increasingly difficult to manufacture vitamin D.  In the UK many of us do not get enough sunlight exposure to generate decent levels of vitamin D in our bodies, especially in the autumn and winter months when we cover our bodies up and don’t get out during the daylight hours very often. 

Walking and exercise have also been linked to improved mood, so a lunchtime walk, in daylight, may bring added mood lifting benefits.  Only small amounts of vitamin D are found in food sources such as oily fish (mackerel, salmon and sardines) and eggs.  As many of us in the UK are falling short of recommended vitamin D levels, if you rarely get out into the sun, you may wish to consider a vitamin D supplement which provides around 12mcg/day (around 500iu a day).  Such a supplement may be particularly useful during the autumn and winter months.

You may also want to think about getting a daylight lamp for your work desk to help improve mood.  Some of these lamps produce light that the body can use for vitamin D production (check with the manufacturer of the lamp).

For more interesting information about the benefits of vitamin D and sunlight for health please visit the Sunlight Nutrition And Health Research Centre, the information there is well presented and backed up by significant amounts of good evidence.

(1)Jorde R et al.  2008.  Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial.  J Intern Med. Sep 10. [Epub ahead of print]
(2)Murphy PK & Wagner CL.  2008.  Vitamin D and mood disorders among women: an integrative review.  J Midwifery Womens Health.  53:440-446
(3)Hoogendijk WJ et al.  2008.  Depression is associated with decreased 25-hydroxyvitamin D and increased parathyroid hormone levels in older adults. Arch Gen Psychiatry. 65(5):508-12.
(4)Johnson MA et al.  2008.  Vitamin D deficiency and insufficiency in the Georgia Older Americans Nutrition Program.  J Nutr Elder.  27:29-46
(5)Berk M et al.  2007.  Vitamin D deficiency may play a role in depression.  Med Hypotheses.  69:1316-1319
(6)Hagenau T et al.  2008.  Global vitamin D levels in relation to age, gender, skin pigmentation and latitude: an ecologic meta-regression analysis.  Osteoporosis International May [E publication ahead of print]
(7) Finch S et at.  1998.  National Diet and Nutrition Survey of People aged 65 Years and Over.  London: H. M. Sationery Office.
(8) 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
(9) 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
(10) 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

Dwindling sunlight and wintry weather may leave some of us feeling a little less positive and uplifted than we would like.  This shift in mood is common, but for some individuals a real sense of depression can occur in the autumn and winter months.  In such cases Seasonal Affective Disorder, or SAD as it is commonly known, may be diagnosed. 

People with SAD frequently suffer sleep disruption, carbohydrate cravings and weight gain, depression, irritability, loss of libido, lethargy, joint pain, stomach problems and often find that their ability to cope seems to be lowered.  Treatment aims to lift mood and relieve depression.  You will be pleased to hear that there are some simple steps that can be taken to help.

Last week I mentioned The Sunlight Campaign being run by the National Osteoporosis Society which aims to highlight the importance of getting out in the sunlight in order for the body to manufacture vitamin D which is crucial for bone health (and many other health parameters!).  Today I wanted to look at the link between sunlight and mood.

The changing seasons can affect our mood and behaviour, this is a natural process that can clearly been seen in animals – and we are no exception.  Many of us will find that we want to eat a little more and sleep a little more in the winter and that the dark mornings and short days are not to our liking.  For some people these kinds of symptoms are severe enough to disrupt normal daily life and cause real distress.  These individuals are said to suffer from SAD.  SAD is characterised by episodes of depression in autumn/winter and is thought to be caused because of lack of daylight.  Our bodies have an internal 24hour clock or cycle, known as the circadian rhythm.  This cycle of day-night is affected when the daylight hours shorten in autumn/winter.  Sunlight is known to affect certain mood chemicals in the brain such as serotonin and melatonin, if there is less light then less serotonin is produced and this may lead to low mood.

Light therapy
Bright light appears to immediately have an effect on mood via the brain chemical serotonin and the pathways involved in its production (1,2,3).  There have been many studies (too many to list), which show the beneficial effects of light therapy for those suffering with SAD.  Light boxes are available to buy online and in stores and do make a real difference.  Make sure that you follow the manufacturers instructions and if you are also seeing a doctor work with them in order to gain maximum benefit.  Most people find that morning use of the light box, for between 30 minutes to an hour, is most helpful.  The light emitted from these units has a similar spectrum to daylight (it is thought hat the light needs to be at least 2,500 lux in order to be beneficial).  Daylight bulbs are also available to buy.

Bright light may actually help us all in the winter.  A study carried out in the year 2000 (4) found that bright light improved vitality and mood among people with SAD but also in healthy subjects with no SAD but who worked indoors during the winter.  This does not surprise me, if you work indoors during the winter months you are more than likely to arrive at work while it is dark, sit in the office in false light and leave when it is dark outside thus never seeing natural daylight.  Getting out for a lunchtime walk or buying a small daylight lamp unit to sit on your desk at work may make a real impact on your mood.

Dawn simulation
Some studies (5,6,7)  have now been carried out with dawn simulators for SAD.  These simulators (daylight alarm clock) are now widely available to buy and usually consist of a unit with a light that gradually increases in intensity over a 30 minute period until it is at it’s brightest when an alarm usually sounds.  The thinking behind the sunrise alarm clock is that in the winter we often wake up with a start when the alarm goes off, but it is still very dark outside.  Our bodies awake with a shock and then we turn on a bright light, we miss the normal cues to the body that occur with dawn and increasing light.  If we wake up with gradual, dawn light our circadian rhythm / natural body clock, is less disrupted.  The studies have proved very positive with some indication that the dawn simulation sunrise alarm clocks, are as good as light boxes at helping mood in SAD sufferers.

Check back later in the week for more information on SAD.

You may also wish to contact the the 'Seasonal Affective Disorder Association' a registered charity which informs the public and health professions about SAD and supports and advises sufferers of the illness.

(1)Grass F & Kasper S.  2008.  Humoral phototransduction: light transportation in the blood, and possible biological effects.  Med Hypotheses.  71:314-317
(2)Aan het Rot M et al.  2008.  Bright light exposure during acute tryptophan depletion prevents a lowering of mood in midly seasonal women.  Eur Neuropsychopharmacol.  18:14-23
(3)Hoekstra R et al.  Effect of light therapy on biopterin, neopterin and tryptophan in patients with seasonal affective disorder.  Psychiatry Res.  120:37-42
(4)Partonen T & Lonnqvist J.  2000.  Bright light improves vitality and alleviates distress in healthy people.  J Affect Disord.  57:55-61
(5)Terman M & Terman JS.  2006.  Controlled trial of naturalistic dawn simulation and negative air ionization for seasonal affective disorder.  Am J Psychiatry.  163:2126-2133
(6) Avery DH et al.  2001.  Dawn simulation and bright light in the treatment of SAD: a controlled study.  Biol Psychiatry.  50:205-216
(7)Avery DH et al.  1993.  Dawn simulation treatment of winter depression: a controlled studyAm J Psychiatry.  150:113-117

Written by Ani Kowal