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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Depression

Summary

Depression is a common condition in the United States. If you have depression you feel fed up, miserable and sad, and these feelings last for more than a few weeks. The symptoms of depression can interfere with your day to day life and for some people can be severe. You may lose interest in life and can’t enjoy anything, find it difficult to make decisions or concentrate and feel unhappy most of the time.

There are many causes of depression. Researchers are now discovering that vitamin D may play an important role in mental health and in depression. Vitamin D acts on the areas of your brain that are linked to depression, but exactly how vitamin D works in your brain isn’t yet fully understood.

There is a growing amount of research into depression and vitamin D. However, the research in this area has given some mixed results.

Research does seem to show a link between low levels of vitamin D in the blood and symptoms of depression. However, research hasn’t yet shown clearly whether low vitamin D levels cause depression, or whether low vitamin D levels develop because someone is depressed. Lack of vitamin D may also be one of many factors that contribute to a depressed mood. There may be many other things that cause depression, which means it’s difficult to say for certain that when depression improves it is vitamin D that is causing the improvement.

Because of all the differences in research studies, and because this is a relatively new area of research, it’s very difficult to say with any certainty what role vitamin D has in either preventing or treating depression.

If you have depression and want to take vitamin D, it is unlikely to make your symptoms worse or cause you any harm. However, you may not see any improvement in your symptoms either. You shouldn’t take vitamin D in place of other treatments or anti-depressant medicines.

What is depression?

We all feel fed up, miserable and sad at certain times in our lives. Most of the time, these feelings last for a week or two and don’t interfere with our day to day lives. When you feel like this you may talk to a friend or family member and after a short time you start to feel better. However, if you have depression these feelings don’t get better and may carry on for weeks or months. They can also start to interfere with your day to day life.

Depression can vary from mild to severe. When it’s mild you may feel in low spirits but you can carry on with your everyday life, though it may feel like harder work and less enjoyable. When depression is at its most severe it can be life-threatening, because you might think about suicide or give up the will to live.

How common is depression?

Depression is a common condition. In the United States around one in 10 people has depression and around one in three of these will have it severely.1 Depression is more likely for some groups of people. You’re more likely to have depression if you:1

  • Have a long term health problem, such as diabetes, heart disease or arthritis.
  • Lead an unhealthy lifestyle, for example if you smoke, drink heavily, are inactive or overweight.
  • Are female
  • Are between 45-64 years of age
  • Are black or Hispanic

What does depression feel like?

People suffering from depression sometimes avoid being with other people.

The symptoms of depression can come on gradually and you may not realize how depressed you are. Sometimes a friend or family member will be the one to notice how your behavior and personality have changed.  Sometimes the symptoms of depression can be physical and you may think you’re just under the weather or tired.

Below are some of the main symptoms of depression (you may not have all of these). You:2, 3

  • Lose interest in life and can’t enjoy anything
  • Find it difficult to make decisions or concentrate
  • Feel unhappy most of the time
  • Feel tired and have problems sleeping
  • Lose confidence and self esteem
  • Avoid being with other people
  • Feel numb, despairing and empty

If you have these symptoms, and they have lasted for more than a few weeks, talk to your physician.

What causes depression?

Depression can be caused by a number of different things. Sometimes there is one main cause, such as the death of a loved one, but sometimes a number of different things may play a part. The causes are different for different people. The main causes of depression are:2

  • Major changes in your life, such as divorce, changing your job, moving home or the death of a loved one.
  • Physical illness – particularly life threatening illness such as cancer, painful conditions such as arthritis and hormone problems such as an underactive thyroid gland.
  • Your circumstances – being alone or stressed for example.
  • Depression in your family – if your parent that has depression you’re much more likely to have it yourself.
  • Your personality – some people seem to be more vulnerable to depression. This may be because of their early life experiences or their genes.
  • Regular heavy drinking.

What is the link between depression and vitamin D?

One theory is that vitamin D affects the amount of chemicals in your brain, like serotonin.

Vitamin D is important for good bone health and researchers are now discovering that vitamin D may be important for many other reasons. It plays an important role in many of the functions of the body, including brain development.

Receptors for vitamin D have been found in many parts of the brain.4 Receptors are found on the surface of a cell where they receive chemical signals. By attaching themselves to a receptor, these chemical signals direct a cell to do something, for example to act in a certain way, or to divide or die.

Some of the receptors in your brain are receptors for vitamin D, which means that vitamin D is acting in some way in your brain. These receptors are found in the areas of your brain that are linked to the development of depression.5 For this reason vitamin D has been linked with depression and with other mental health problems.

Exactly how vitamin D works in your brain isn’t fully understood. One theory is that vitamin D affects the amount of chemicals called monoamines (such as serotonin) and how they work in your brain.5 Many anti-depressant medicines work by increasing the amount of monoamines in your brain. Therefore researchers have suggested that vitamin D may also increase the amount of monoamines, which has an effect on depression.5

What does the research say in general about vitamin D and depression?

The amount of research about vitamin D and depression, and other mental health problems, is growing. This is a complex research area and it’s only recently that large studies on vitamin D and depression have been carried out.

The research in this area has given some mixed and conflicting results.5 One of the reasons for this is that there are very few research studies where it’s possible to compare like with like.6 Researchers:

  • use different amounts of vitamin D supplements for different lengths of time
  • judge the effectiveness of treatment using different vitamin D blood levels
  • test different groups of people in their studies
  • measure depression and mental health in different ways
  • give vitamin D at different frequencies- in some studies people are asked to take vitamin D every day, where as in other studies people take vitamin once a week.

In some research studies, the amount of vitamin D given has been small, much less that the 5000IU a day that the Vitamin D council recommends. This means that in these research studies the small dose may affect whether there is any effect on the symptoms of depression.

Because of all the differences in research studies, and because this is a relatively new area of research, it’s very difficult to say with any certainty what role vitamin D has in either preventing or treating depression.

So, what does recent research say?

There are a number of good research studies from the last few years that look specifically at vitamin D and depression.

In a review of research about vitamin D and depression in 2013,9 researchers looked for and analysed all of the published research about depression and vitamin D up until February 2011. They looked at good quality research studies that explored whether:

  • a lack of vitamin D in your blood is linked with being depressed
  • a lack of vitamin D in your blood makes it more likely you will develop depression
  • taking a vitamin D supplement can improve or prevents depression

The researchers found more than 5000 research articles, however just 13 explored this area effectively. More than 31000 people took part in these 13 studies. The results showed that there is a relationship between low levels of vitamin D in the blood and depression. However, the research didn’t show whether vitamin D was the cause or effect of depression. There was also no clear answer as to whether taking supplements was effective at treating or preventing depression.

A 2008 research study from Norway7 found that people with a low level of vitamin D in their blood had more symptoms of depression. This research also found that taking vitamin D, particularly in large amounts, improved the symptoms of depression. The biggest effect happened in those people with more severe symptoms.

However, this research only looked at people that were overweight, so it’s not possible to say whether the results would be similar for everyone. All of the participants also took a calcium supplement, and the researchers suggest that this could have affected the results, for example it could be vitamin D and calcium working together, rather than vitamin D on its own, that effects depression.

A second research study from Norway5 looked at whether the symptoms of depression were related to vitamin D blood levels. The study also looked at whether taking a vitamin D supplement affected the symptoms of depression in people that had low vitamin D levels. The results showed that:

  • low levels of vitamin D in the body are linked to the symptoms of depression
  • when people with low vitamin D levels took a supplement, it improved their vitamin D levels, but had no effect on their symptoms of depression
  • low vitamin D levels could be the result, rather than the cause of depression

Although this study used a good amount of vitamin D supplement, it lasted for only six months. The researchers suggest that because depression is a condition that tends to develop slowly and last a long time, a longer study might have shown different results. Those who took part also had either no symptoms of depression or very mild symptoms, and this may have influenced the results.

Vitamin D and depression in women

A study published in 20126 from researchers in the United States showed that there was no difference in depression symptoms between those women who took vitamin D and those women who took dummy tablets.

The study looked at a very large group of women and was the first study of this kind to do so.  The researchers suggest that the amount of vitamin D that the women took may have been too small to have an effect on the symptoms of depression. The participants taking vitamin D also took a calcium supplement, and the researchers suggest that this could have affected the results. For example it could be vitamin D and calcium together, rather than vitamin D on its own, that effects depression.

Another study from 201210 showed that taking vitamin D supplements had no effect on depression in older women. The women in the study took either a vitamin D supplement, or hormone therapy, or both together.  Researchers also took blood samples to see whether there was a link between the symptoms of depression and vitamin D receptors on the cells of the body. No link was found.

This was a large, good quality research study which ran for a long time (three years). However, the researchers suggest that there may not have been enough women with depression who also had very low levels of vitamin D taking part, and this may have affected the results.

Key points from research

  • Research does seem to show a link between low levels of vitamin D in the blood and symptoms of depression.
  • Research hasn’t yet shown clearly whether low vitamin D levels cause depression, or whether low vitamin D levels develop because someone is depressed.5
  • Lack of vitamin D may be one of many factors that contribute to a depressed mood. There may be many other things that cause depression, which means it’s difficult to say for certain that when depression improves it is vitamin D that is causing the improvement.7
  • The effects of vitamin D on depression may take a long time to work, years for example.8 This means that research carried out over short periods of time may not show any impact of vitamin D on depression.
  • People who have depression go outdoors less, so they are less likely to have good amounts of vitamin D in their blood.8
  • Some researchers have suggested that giving vitamin D supplements may work for depression when someone has very low levels of vitamin D to begin with.8 Taking a vitamin D supplement may work less well for people who already have good vitamin D levels.
  • Taking vitamin D may only have a role to play if you’re already depressed.5

What does this mean for me?

We don’t know yet whether taking a vitamin D supplement, or getting more vitamin D by exposing your skin, will help to ease the symptoms of depression or prevent depression.

Research does seem to show that there is a link between vitamin D and depression. However, we don’t know exactly what that link is.

Research has not yet shown clearly whether low levels of vitamin D cause depression, or whether depression causes low levels of vitamin D. This means that we don’t know whether taking a vitamin D supplement, or getting more vitamin D by exposing your skin, will help to ease the symptoms of depression or prevent depression.

If you have depression and want to take vitamin D, it is unlikely to make your symptoms worse or cause you any harm (as long as you’re taking less than 10,000 IU/day). However, you may not see any improvement in your symptoms either.

If you have depression you shouldn’t take vitamin D in place of other treatments or anti-depressant medicines. Speak to your physician for more advice about treatments and taking supplements.

Did you know?

Exposing your skin to the sun to get vitamin D enhances your mood and energy. Generally, a little bit of sun exposure is linked to a better mood, while tanners commonly report feeling more relaxed than non-tanners. One research study showed that β-endorphins increase after sun exposure, and β-endorphins make you feel good!

References

  1. Current Depression Among Adults -United States, 2006 and 2008. Centres for Disease Control and Prevention. http://www.cdc.gov/features/dsdepression/, published 2010
  2. Depression. Royal College of Psychiatry. http://www.rcpsych.ac.uk/mentalhealthinfoforall/problems/depression/depression.aspx
  3. Depression. MIND. http://www.mind.org.uk/help/diagnoses_and_conditions/depression
  4. Eyles D W, Smith S, Kinobe R et al. Distribution of the vitamin D receptor and 1alpha-hydroxylase in human brain. J Chem Neuroanat. 2005;29: 21-30.
  5. Kjaergaard M, Waterloo K, Wang K etc al. Effects of Vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised trial. Br J Psychiatry. 2012 Jul 12.
  6. Bertone-Johnson E R, Powers S I, Spangler L et al. Vitamin D Supplementation and Depression in the Women’s Health Initiative Calcium and Vitamin D Trial. Am J Epidemiol 2012; 176(1):1-13
  7. Jorde, M. Sneve, Y. Figenschau, J et al. Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial. J Intern Med. 2008;264(6):599-609
  8. Dean A J, Bellgrove M A, Hall T et al. Effects of vitamin D supplementation on cognitive and emotional functioning in young adults–a randomised controlled trial. PLoS One. 2011;6(11):e25966
  9. Anglin R, Samaan Z, Walter S et al. Vitamin D deficiency and depression in adults: systematic review and meta analysis. British Journal of Psychiatry, 2013.
  10. Yalamanchili V, Gallagher C. Treatment with hormone therapy and calcitrol did not affect depression in older post menopausal women: no interaction with estrogan and vitamin D receptor genotype polymorphisms. Menopause, 2012.

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This page was last updated June 2013.

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